THINK QUESTIONS Chapter 1: Introduction

Transcription

1 THINK QUESTIONS Chapte 1: Intoduction (1) Diffeent cop species oiginated in diffeent egions of the wold. List the centes of oigin of the following ten cop species: Onion (Allium spp), Alfalfa (Medicago sativa), Rice (Oyza sativa), Potato (Solanum tubeosum), Soybean (Glycine max), Millet (Eleusine coacana), Cotton (Gossypium spp.), Sunflowe (Helianthus spp.), Wheat (Titicum spp.), and Apple (Malus spp.). () A combination of natual selection, and selection diected by plant beedes (ealy and moden) has influenced the cops we now gow. List five chaacteistics that mankind has selected which would not have been selected by a pocess of natual evolution (3) The yield of many cops species has isen damatically ove the last 50 yeas. This has been the diect esult of plant beeding duing this peiod and hence the tend is likely to continue ove the next 50 yeas. Biefly discuss this statement. (4) The place of oigin of cops, thei histoy and evolution ae events fom the past and theefoe have no elevance to moden plant beeding Tue o False? Discuss you answe. (5) Many believe that civilization (of humans) stated with the beginnings of agicultue. Basically thee ae two foms of agicultue: (1) eaing animals fo meat, milk etc. and () aising cops fo human o animal feed. No one knows which fom of agicultue evolved fist (o maybe both types stated togethe). Explain why (in you opinion) one fom came befoe the othe o both foms evolved at the same time. (6) A combination of natual selection, and selection diected by plant beedes (ealy and moden) have influenced the cops we now gow. Have moden plant beedes impoved the genetic fitness of ou agicultual cop species, o have they simply selected plant types that ae moe suited to moden agicultual systems? (7) A temendous amount of plant divesity exists within Austalia. Why, theefoe, ae thee few Austalian aboiginal fames, and almost none of today s wold cop species had thei cente of oigin in the Austalian continent? (8) You ae difting you way though life when thee is a cash and a temendous flash of light, and fom nowhee an alien space ship lands. The alien, speaking pefect English, says I bing to you a gift; the Univese's most poductive and pefect cop species. Theeafte the alien gives you a bag of 00 seeds, etuns to the space caft and whoosh, it's gone. Descibe what you would do with the seeds and what infomation you would collect that would allow you to develop new cultivas fom these seeds. Chapte : Modes of Repoduction and Types of Cultiva (1) Complete the following table by assigning a YES o NO to each of the 16 cells. Ae these cultivas compised of only one single genotype? Is heteosis a majo yield facto in esulting cultivas? Pue-line Open Hybid Clonal cultiva pollinated cultiva cultiva cultiva

2 Ae esulting cultivas popagated by means of botanical seeds? Can the seed, o plant pats, of a cultiva be used fo its own popagation? () Inbeeding and out-beeding species tend to have diffeent chaacteistics. Explain factos that would detemine if a given species should be classified as inbeeding o out-beeding. (3) A numbe of diffeent cultiva types ae available in agicultue. Outline the majo featues of the following cultiva types: a.hybid cultivas; b. Pue-line cultivas; c. Clonal cultivas; d. Multiline cultivas; e. Open-pollinated cultivas and f. Synthetic cultivas. (4) List two inbeeding cop species and two out-beeding cop species that have been exploited as (q) pue-line cultivas; (b) open pollinated cultivas; (c) hybid cultivas; (d) clonal cultivas; (e) Multiline cultivas and (f) synthetic cultivas. (5) Descibe the majo featues of the following types of apomixis: Diplospoy; Semigamy; Pathenogenesis; Apospoy. (6) List five diffeent plant pats that can be used fo asexual epoduction. Chapte 3: Beeding Objectives (1) Explain the diffeence between vetical and hoizontal disease esistance and outline the advantages o disadvantages of each fom of esistance as it elates to cultiva development. () Outline the majo featues involved in selecting fo end-use quality and indicate any paticula poblems that beeding fo impoved quality might cause. (3) When beeding new cultivas it is often necessay to ty and pedict events that may occu in the futue. Biefly outline fou factos which may influence cultiva beeding and hence need to be consideed in setting the beeding objectives of a cultiva development pogamme. (4) In plant beeding, two main disease esistance mechanisms exist, inhibition of infection and inhibition of gowth afte infection. Explain each of these mechanisms. (5) Choose any agicultual/hoticultual cop (e.g. wheat, baley, potato, apple, hops, etc.) and outline a set of beeding objectives to be used to develop new cultivas. Indicate potential makets fo the new cultivas. (6) Explain, using examples as necessay, the meaning of the tems plant toleance and plant escape in elation to pest and disease esistance and plant beeding. (7) Fou loci affecting powdey mildew disease have been identified at which single, dominant, disease esistance alleles (coded, A, B, C, and D) each offe complete immunity to a specific ace of powdey mildew (with alleles a, b, c and d each showing susceptibility). iulence genes have also been identified in the pest (A a', B, b', C, c', and D, d'). Given the infomation below, indicate whethe each genotype would be esistant o susceptible to the disease. Plant genotype Mildew genotype Plant esponse

3 AAbbCCdd AaBbCcDd aabbccdd Aabbccdd A'a'B'B'c'C'd'd' A'a'B'b'C'c'D'd' A'A'b'b'C'c'd'd' A'A'B'B'C'C'D'D' (8) You have been offeed a job as Senio Plant Beede with the Dyeye Onion Company in Southen Idaho. You fist task in this new position is to set beeding objectives fo onion cultiva development ove the next 1 yeas. Outline the main points to be consideed when setting you beeding objectives; indicate what questions you would like answeed to enhance the beeding objectives you will set. What might be the main souces of infomation that you would use to aive at you esponse? Chapte 4: Beeding Schemes (1) Disease esistance to powdey mildew has been identified in a pimitive, uncultivated species which is elated to cultivated baley (Hodeum vulgae). Reseach has shown that the esistance is contolled by a single dominant allele (notation = RR). Thee is a esistance sceen test available which shows 100% eliability. Diagammatically, outline a beeding scheme that could be used to intogess this chaacte into an existing cultiva ( Golden Pomise ) which is susceptible to powdey mildew (notation = ). The aim is fo the esulting esistant lines to compise at least 96% of the Golden Pomise genotype. Conside now that the disease esistance is contolled by a single ecessive allele, how would this effect the beeding method you have descibed above. () Cop cultivas can be divided into pue-line cultivas, open-pollinated populations, hybid cultivas o clonal cultivas. Biefly, descibe the majo poblems that can be encounteed o the attibutes of the cop types that can be utilized, when beeding: a pue-line cultiva; a open-pollinated population; a hybid cultiva and a clonal cultiva. (3) You have been appointed as alfalfa (Medicago sativa L.) beede to develop cops fo the Alfed Alfoncia Seed Company Ltd. Outline a suitable beeding scheme you will use to develop supeio synthetic cultivas fo you new employe. Show each stage of the scheme on a yea-by-yea basis. Afte seveal ounds of clonal selection, you have identified 4 potential highly poductive paent lines fo developing a new synthetic (lines ae coded as A, B, C and D). Hybid seed was poduced fom all two-paent coss combinations possible and these wee evaluated in yield tials along with the paent lines. Fom the yield (Kg) esults (below) indicate the thee paent synthetic most likely to be highest yielding and state the expected yield. Paent A = 18; Paent B = ; Paent C = 1; Paent D = 5 (4) Outline thee chaacteistics of a cop species that would meit consideation befoe developing hybid cultivas fom that species. (5) Outline the advantages and disadvantages of a bulk beeding scheme and a pedigee beeding scheme to develop pue-line cultivas

4 Many beeding schemes fo pue-lines ae a combination of bulk and pedigee schemes. Design a suitable bulk/pedigee beeding scheme (it is not necessay to make notes on when specific chaactes ae selected) that could be used to develop supeio pue-line cultivas. Outline any advantages o disadvantages of you beeding scheme. (6) A hybid beeding pogamme has identified six supeio inbed lines (A, B, C, D, and E) which wee inte-cossed in all combinations and the F 1 pogenies evaluated fo poductivity in a field yield tial. The esults fom each single coss in the tial wee: A x B = 60 A x C = 65 A x D = 51 B x C = 63 B x D = 61 B x E = 59 C x E = 4 C x F = 37 D x E = 5 A x B = 60 A x C = 65 A x D = 51 B x C = 63 B x D = 61 B x E = 59 Which paent combination will povide the most poductive single coss hybid and what would the expected yield be? Which paent combination will povide the most poductive thee-way coss hybid and what would the expected yield be? Which paent combination will povide the most poductive double coss hybid and what would the expected yield be? Explain why the most poductive double coss combination (fom the pediction equation), may not esult in the most commecially suited hybid cultiva. (7) In ode to justify development of hybid cultivas it is necessay to have some method of poducing inexpensive hybid seed. Outline thee systems that have been used to poduce hybid seed and indicate the advantages o disadvantages of each system. (8) Russet Bubank has been the pedominant potato cultiva in the Pacific Nothwest fo many yeas. You have been asked to design a beeding pogamme that will poduce cultivas that can eplace some of the Russet Bubank aceage. Outline the beeding design you would use, indicating: (a) five beeding objectives; (b) the beeding scheme (use diagams if necessay), and (c) indicating the numbe of clones evaluated and selected at each stage. (9) In ode to poduce a hybid cultiva using cytoplasmic male steility you equie thee types of genotypes. Descibe the diffeence between the thee types equied, and descibe how commecial poduction will be conducted. (10) You ae to embak on a backcossing study designed towads convegence beeding. You have at you disposal two genotypes coded C and M. Genotype C is a cytoplasmic male steile line, but one that does not have vey good hybid combining ability; genotype M has geat hybid combining ability and is male fetile (without a male fetile estoe gene). Design a scheme (listing each opeation necessay) that will esult in a genotype which is 95% the nuclea genotype of the M line but is cytoplasmically male steile. (11)You ae walking along a deseted beach in Southen Califonia (ae thee any of these left?) and you inadvetently kick a bass oil lamp. On picking up the lamp you gently ub the side and poof! a 0 foot tall genie appeas! Oh maste! says the genie, I can gant you two wishes (well times ae had and the old thee wishes ule does not apply any moe). You think fo a few minutes then say I would like you to conjue me up the most wondeful plant that exists within the Univese, so that I can gow it on my fam in Idaho and

5 make millions of dollas in pofits. Poof! This plant appeas befoe you. A plant species that has neve been seen on eath befoe. As a plant beede, list five questions you would ask the genie about the biology of this plant that would help you design a cultiva development pogamme to incease the value of it as a cop. Having soted that out, you begin to think of you othe wish. I would like you to tell me the fomula fo a chemical apomict (a chemical, when applied to a cop will esult in 100% apomictic seed fom the cop). Well says the genie. I can do this, but, you must specify which cop species the chemical will wok on (it can only wok on one chosen species). What cop species would you chose to have apomictic seeds, and why? Chapte 5: Genetics and Plant Beeding (1) A coss is made between two homozygous baley plants. One paent is dominant fo a tall statue gene (TT) and has a single dominant esistance to yellow ust (YY), but highly susceptible to powdey mildew (mm). So the genotype of the fist paent can be epesented by TTYYmm. The othe paent has shot statue (i.e. ecessive dwafing gene, tt) with single (completely dominant) esistance to powdey mildew (MM), but is susceptible to yellow ust (yy). So the genotype of the second paent can be epesented by ttyymm. Conside if a sample of F 1 plants fom this coss wee self pollinated, and used to poduce a population of 1,800 F plants. At the havest of these F plants the shot (dwaf) plants wee selected and only seed fom these plants was planted out in head-ows at F 3. How many of the F 3 head-ows would be esistant to both yellow ust and powdey mildew? How many will be esistant to powdey mildew but susceptible to yellow ust? And, how many will be susceptible to both diseases? () In a beeding expeiment simila to that in question 1, a coss is made between two homozygous baley plants. One paent is tall and with shot leaf magin hais (TTss), and the othe is shot with long leaf magin hais (ttss). Single genes contol both plant height and leaf magin hai length. Tall plants (T_) being completely dominant to shot (tt), and long leaf magin hais (S_) dominant to shot (ss). A sample of F 1 plants wee self-pollinated and 1,600 F plants evaluated fo plant height and leaf magin hai length. Afte evaluating the phenotypes it was found that thee wee: tall plants with long leaf magin hais; tall plants with shot magin hais; 0 - shot plants with long leaf magin hais; and shot plants with shot magin hais. Give an genetic explanation of what undelies the obseved fequency of phenotypes and test you theoy using a suitable statistical test. (3) A sping wheat beeding pogam aims to develop cultivas that ae esistant to foot-ot (contolled at a single locus with a completely dominant allele (FF) confeing esistance), and that ae also esistant to yellow stip ust, (contolled at a single locus with a single dominant (YY) allele confeing esistance). A coss is made between two paents whee one paent is

6 esistant to foot ot and susceptible to yellow stip ust (FFyy) while the othe is esistant to yellow stip ust but susceptible to foot ot (ffyy). The heteozygous F 1 is cossed to a double susceptible homozygous line with genotype ffyy and,000 BC 1 pogeny wee evaluated fo disease esistance. The following numbes of phenotypes wee obseved: Resistant to both foot ot and yellow stip ust = 90 Resistant to foot ot but susceptible to yellow stip ust = 893 Susceptible to foot ot but esistant to yellow stip ust = 907 Susceptible to both foot ot and yellow stip ust = 110 Detemine the pecentage ecombination between the foot ot and yellow stip ust loci. Given the fequency of phenotypes with the above pecentage ecombination, how many F plants would need to be evaluated to be 99% cetain of obtaining at least one plant that is esistant to both foot ot and yellow stip ust? In contast, how many would need to be evaluated to be 99% cetain of obtaining at least one plant that is esistant to both foot ot and yellow stip ust, given independent assotment of the two loci involved? (4) Potato cyst nematode esistance is contolled by a single locus with a completely dominant allele (R). A coss is made between two auto-tetaploid potato cultivas whee one paent is esistant to potato cyst nematode and the othe is completely susceptible. Pogeny fom the coss ae examined and it is found that 83.3% of the pogeny ae esistant to potato cyst nematode. What can be detemined about the genetical status of the esistant paent in the coss? A beeding pogam aims to poduce potato paental lines that ae eithe quaduplex o tiplex fo the potato cyst nematode esistant allele R. A coss is made between two paents, which ae known to be duplex fo the esistant allele R. What would be the expected genotype and phenotype of pogeny fom this duplex x duplex (i.e. RR x RR) coss? (5) Why ae plant beedes inteested in conducting scaling tests fo quantitatively inheited chaactes of impotance in the beeding scheme? A popely designed expeiment was caied out in canola whee paent lines (P 1 and P ), ae gown alongside F 1 and F pogeny plants fom the coss P 1 x P. The aveage yield of plants fom each of the fou families, the vaiance of each family and the numbe of plants evaluated fom each family wee: Family Mean yield aiance of yield Numbe of plants P 1 1, P 1, F 1 1,

7 F 1, Use an appopiate test to detemine whethe the additive/dominance model of inheitance is adequate to explain the genetic vaiation in yield in canola. What can you conclude fom the esults obtained above? What could have caused this to occu? (6) Assuming an additive/dominance mode of inheitance fo a polygenic tait, set out the paametes to descibe P 1, P, and F 1 in tems of m, [a] and [d] and then similaly fo F, B 1 and B Fom a popely designed field tial that included B 1, B and F 1 families, the following yield estimates wee obtained. B 1 = 4.0 kg/ace; B = 6.0 kg/ace; F 1 = 38.5 kg/ace Fom these family means, estimate the expected value of P 1, P, and F, based on the additive/dominance model of inheitance (7) A coss is made between two homozygous baley plants. One paent has a two-ow ea (contolled at a single locus by a ecessive allele (hh) (as opposed to the dominant six-ow (HH)) and is dominant fo a tall statue at the T locus (TT), is esistance to yellow ust (YY - completely dominant), but highly susceptible to powdey mildew (i.e. TThhYYmm). The othe paent has a six-ow ea (HH), shot (dwaf, tt), esistant to powdey mildew, but is susceptible to yellow ust (i.e. tthhyymm). All tait loci ae located on diffeent chomosomes. A sample of F 1 plants fom this coss wee self pollinated, and a population of 9,160 F plants gown. At havest the shot (dwaf) plants with two-ow eas ae selected and only seed fom these plants ae gown out in head-ows at F 3. How many of the F 3 head-ows would be esistant to both yellow ust and powdey mildew? How many will be esistant to powdey mildew but susceptible to yellow ust? And, how many will be susceptible to both diseases? (8) Two homozygous squash plants wee hybidized and an F 1 family poduced. One paent had long, geen fuit ( LLGG ), and the othe had ound, yellow fuit ( llgg ) F pogeny wee examined fom selfing the F1 s and the following numbes of phenotypes obseved: LLGG L-gg llg- llgg Complete an appopiate analysis to explain and intepet this segegation patten. Chapte 6: Pedictions

8 (1) Given values fo the vaiance of the mean of the F, and vaiance of the F 1, estimate and explain what this tells us about the genetic detemination of the tait. F F h b Given below ae the vaiances of the mean fom two paents (P 1 and P ), the F 1, F, and both backcoss families (B 1 and B ), estimate in genetic tems P1 P F1 F B1 B h n and explain what the value means () List the six assumptions necessay fo a staight fowad intepetation of a Hayman and Jinks Analysis of diallels. Below ae shown values of aay means, within aay vaiances ( ) and covaiances between aay values and non-ecuent paents ( W ) fom a Hayman and Jinks Analysis of a 7 7 complete diallel in dy pea. Paent name W Aay mean Soupe Dleiyon Yielde Shatte Ceamy SweetP Lime

9 The tait of inteest is pea gain yield. Regession of equation: W against esulted in the W , with standad eo of the egession slope equal to se b = An analysis of vaiance of W showed significant diffeences between aays while a simila analysis of W showed no significant diffeences between aays. What can be deduced egading the inheitance of pea yield fom the infomation povided? If you wee a plant beede inteested in developing high yielding dy pea cultivas, on which two paental lines would you concentate you beeding effots? Biefly explain why. (3) Below is shown an analysis of vaiance of plant yield fom a 6 6 half diallel (including paents). The analysis of vaiance is fom a Giffing s Analysis (Model ). GCA geneal combining ability, SCA specific combining ability, Eo eo obtained by eplication, df degees of feedom and SS sum of squae. Souce df SS GCA SCA Eo Discuss the esults fom the analysis given that the 6 paents wee: (a) specifically chosen, and (b) chosen completely at andom. (4) It is desied to detemine the naow-sense heitability fo floweing date in sping canola (B. napus). Both paents and thei offsping fom ten coss combinations wee gown in a popely designed field expeiment. At havest, yield was ecoded fo each enty and using these data the aveage phenotype of two paents (i.e. [P 1 P ] ) was consideed to be x, the independent vaiable, while the pefomance of thei offsping was consideed as y the dependant vaiable. A egession analysis is to be caied out by egession of the, offsping ( y ) onto the aveage paent ( x ). The following data ae deived: SP( xy) ; SS( x ) ; SS ( y) Estimate the slope of the egession line (b), test if this slope is geate than zeo and estimate the naow-sense heitability fom the egession equation. How would the elationship between the egession and the naow-sense heitability diffe if the egession wee caied out between only the offsping and the male paent? (5) Fou types of diallel can be analyzed using a Giffing s Analysis. Descibe these types. Families fom a 5 5 half diallel (including selfs) wee planted in a two eplicate yield tial at a single location. The paents used in the diallel design wee chosen to be the highest yielding lines gown in the Pacific-Nothwest egion. Data fo yield wee analyzed using a Giffing s Analysis of vaiance. Family means, aveaged ove two eplicates,

10 degees of feedom and sum of squaes (SS) fom that analysis ae shown below. Intepet the esults fom the Giffing s Analysis. What diffeences would thee be in you analytical methods if the paents used had been chosen at andom. Paent 1 Paent Paent Paent Paent 3 Paent Paent 4 Paent Paent 5 Paent Souce d.f. SS GCA SCA Replicates Eo Total Fom the same diallel data (above), within aay vaiances ( ) and between aay and non-ecuent paent covaiances ( W ) wee calculated. The values of and W fo each paent along with the mean of, mean of W, sum of squaes if ( ), sum of squaes of W ( W ) and sum of poducts W ae shown below. W Mean of ; Mean of W ; : W ; W Fom these data, test whethe the additive-dominance model is

11 adequate to descibe vaiation between the pogenies. What can be detemined about the impotance of additive compaed to dominance genetic vaiation in this study. Fom all the esults (Giffing and Hayman and Jinks, above) which two paents would you use in you beeding pogamme and why? (6) Given the vaiance fom two paents (P 1 and P ), the F 1, F, B 1 and B families, estimate the naow-sense heitability ( h ) n and explain what the value means in genetical tems P1 P F1 F B1 B (7) A new oil cop (Bassica gasolinous) has been discoveed which may have potential as a biologically enewable fuel oil substitute. This diploid species is toleant to inbeeding and is self-compatible. A peliminay genetic expeiment was designed to examine the inheitance of seed yield (YIELD) and pecentage oil content (%OIL). This expeiment involved a 4 4 half diallel (including selfs). The fou homozygous paental lines ae epesented by the codes AAA, BBB, CCC and DDD. The half diallel aay values (aveaged ove two eplicates), aay means, geneal combing ability (GCA) values, mean squaes fom the analyses of vaiance (Giffing style), and W values (Hayman and Jinks analysis), vaiance of aay means ( x ) and paental vaiances ( ) p, and the oneway analyses of vaiance fo W and W ae shown below fo each chaacte. Yield %Oil AAA BBB CCC DDD AAA BBB CCC DDD AAA BBB CCC DDD Aay means Souce df Yield %Oil G.C.A S.C.A Replicate

12 blocks Replicate eo and values W Yield %Oil W W AAA BBB CCC DDD x and p values Yield %Oil x p Yield %Oil Souce df W W W W Between Within Without using egession, estimate the naow-sense heitability ( h fo seed yield, and explain this value in tems of genetic vaiance. Explain the analyses fo Yield and outline any conclusions that can be dawn fom these data. Explain the analysis fo %Oil (pecentage of seed weight that is oil) and outline any conclusions that can be dawn fom these data. Which one of these fou genotypes would you choose as a paent in you beeding pogamme? Explain you choice. Descibe any difficulties suggested fom these analyses in a beeding pogamme designed fo selecting lines with high yield and high pecentage of oil. n ) (8) F 1, F, B 1 and B families wee evaluated fo plant yield (kg/plot) fom a coss between two homozygous sping wheat paents. The following vaiances fom each of the fou families wee found:

13 F1 F B1 B Calculate the boad-sense ( h and naow-sense ( h heitabilities fo plant yield. ) b Given the heitability estimates you have obtained, would you ecommend selection fo yield at the F 3 stage in this wheat beeding pogamme, and why? n ) (9) Giffing has descibed fou types of diallel cossing designs. Biefly outline the featues of each Method 1,, 3 and 4. Why would you choose Method 3 ove Method 1? Why would you choose Method ove Method 1? A full diallel, including selfs was caied out involving five chickpea paents (assumed to be chosen as fixed paents), and all families esulting wee evaluated at the F 1 stage fo seed yield. The following analysis of vaiance fo geneal combining ability (GCA), specific combining ability (SCA) and ecipocal effects (Giffing s Analysis) was obtained: Souce d.f. MS GCA 5 30,769 SCA 10 10,934 Recipocal 10 9,638 Eo 49 5,136 Complete the analysis of vaiance and daw conclusions fom the analysis. If it was actually the case that the paents wee chosen at andom, how would this change the esults and you conclusions? Plant height was also ecoded on the same diallel families and an additive-dominance model found to be adequate to explain the genetic vaiation in plant height. Aay vaiances s and non-ecuent paent covaiance s ( W s) wee calculated and ae shown alongside the geneal combining ability (GCA) of each of the five paents, below: Paent W GCA

14 Without futhe calculations, what can be deduced about the inheitance of plant height in chickpea? (10) A 4 4 half diallel design (with selfs) was caied out in lentils and the following seed yields of each possible F 1 family wee obseved: Small eds Small eds 1 Big yields Big yields 7 36 Jim s delight Jim s delight Jacks best Jack s best Fom the above data, detemine the naow-sense heitability fo yield in chey. (11) A cossing design involving two homozygous pea cultivas was caied out and both paents wee gown in a popely designed field expeiment with the F, B 1 and B families. Given the following standad deviations fo paents (P 1 and P ), the F, and both backcoss pogeny (B 1 and B ), detemine the boad-sense heitability and naow-sense heitability fo seed size in these dy peas. What can be concluded fom the values of heitability you obtained? Family Standad aiance deviation P P F B B (1) It is common in plant beeding pogams to cay out diallel analyses to detemine the genetics of specific paents and thei pogeny. With paticula efeence to diallel intepetation, explain the tems fixed and andom paents, and how choosing one o othe would influence the analyses of a Giffing ANOA. Giffing's analysis of diallels is a statistical analysis based on the following model:

15 Y ijk = + g i + g j + s ij + e ijk Descibe the meaning of the tems in the g j and s ij in the Giffing model, above. Below ae the mean seed yields, aveaged ove fou eplicates, of the paents and offsping fom a 3x3 half diallel, with selfs. Sunise Sunise 16.4 Pemie Pemie Cleawate Cleawate Hyola.401 Hyola Using these data, detemine the g i value of each paent and estimate the s ij value in the coss Hyola.401 x Pemie. (13) A newly appointed baley beede was inteested in the inheitance and heitability of yield in sping baley. He chose five cultivas fom a ange that wee gown thoughout his taget egion and intecossed them in all possible coss combinations (excluding ecipocals) including selfs, and he completed a Hayman and Jinks analyses. Some of the esults ae shown below. Cultiva Mean Yield i W i Pemie Sunise Reape Lifeline Sta Mean The egession equation of W i onto i is: W i = x i.15, and the standad eo of the slope is The vaiance of paents ( p ) is 4.37, and the vaiance o aay means ( x ) is 16.77

16 Complete the Hayman and Jinks analyses of vaiance, detemine whethe the additivedominance model is appopiate, calculate the naow-sense heitability and descibe what can be detemined about the inheitance of yield in sping baley. Chapte 7: Selection (1) Selection in a plant beeding pogamme can be divided into thee diffeent stages: ealy geneation selection, intemediate geneation selection and advanced geneation selection. Biefly, state the majo diffeences between these thee stages. () A half diallel cossing design was used to examine the potential of each of ten paents in a wheat beeding pogamme. F 1 families along with each of the paents wee gown in a popely designed field tial. Yield (kg pe plot) was ecoded and fom the data, aay means, within aay vaiances ( s) and between aay covaiances ( W s) wee estimated. These statistics ae shown below. Fom this infomation detemine which thee of the ten potential paents would be best suited fo use in a cultiva development scheme designed to incease wheat yield? Explain you choices. Paent Mean W (3) In a bean beeding pogamme, it is desied to poduce new cultivas which ae shot (dwaf) in statue and that have oval shaped beans (athe than ound). Both bean shape and dwafism ae contolled by single loci with two alleles at each. The allele fo oval beans is dominant to the altenative allele fo ound beans. The dwafing allele is ecessive to the non-dwaf (tall) allele. A coss is made between two homozygous paents whee paent 1 is dwaf with ound beans (tt ) while paent two is tall with oval beans (TTRR). A numbe of F 1 plants ae selfed to poduce F seeds fom which 1600 F plants ae gown. Assuming independent assotment

17 of genes, outline a selection scheme which will esult in havesting F 4 seeds that ae homozygous fo oval beans and dwaf statue. Indicate the numbe of plants selected at each selection stage. (4) You ae a potato beede woking in a publicly funded oganization. Due to the beak-up of the fome Soviet Union, you have inheited 500 potato lines fom the Sibeian Potato Reseach Cente. Biefly outline (using diagams if necessay) how you would sceen these genotypes fo thei potential as new paents in you beeding pogamme. (5) In a winte apeseed beeding pogamme 3000 nea-homozygous beeding lines wee evaluated fo yield and oil content fom a popely designed field tial. The coelation coefficient between yield and oil content was found to be Using independent culling you want to select the highest yielding 10 pe cent and select fo oil content etaining the best 15 pe cent. How many genotypes would you expect to be: (1) selected fo high yield and high oil content; and () selected fo high yield but discaded fo high oil content? (6) Independent culling can be a vey effective means to select fo two o moe chaactes simultaneously and can be easily applied to beeding data. Unde what cicumstances would independent culling not be vey effective? If index selection is used, list two methods that could be used to weight the taits. (7) 50 pogeny fom ten potato cosses wee evaluated fo yield in a popely designed field tial. Fom the esults the following coss means and genetic vaiances ( ) wee obtained: g Mean g Coss Coss Coss Coss Coss Coss Coss Coss Coss Coss Also gown in the same tial wee ten commecial cultivas. The aveage pefomance of the commecial cultivas was 0.14 and the standad deviation was 3.6. Using univaiate coss pediction pocedues detemine which thee cosses should be used in beeding fo cultivas which would have high yields. Rank you choices as fist, second and thid and include the pobabilities used fo you decision, unde the following citeia:

18 Geate than aveage contols plus one contol standad deviation Geate than the aveage contol plus twice the contol standad deviation. Using the data pesented above, how many clonal lines would need to be aised fom Coss 6 to be 90% cetain of having one line which would have a yield potential exceeding 3 standad deviations fom the contol mean. (8) A half diallel cossing design is caied out involving 30 homozygous paents. F 3 pogeny fom each of the 435 possible coss combinations wee aised and gown in a two eplicate yield tial (planting F 3 and havesting F 4 seed). Also gown within the tial wee all 30 paental lines. Based on the yield esults fom the tial it was found that the egession of pogeny pefomance ( y ) onto mid-paent value ( x ) was: y 0 83x 0 00 Also fom this tial, the phenotypic vaiance of the F 3 families was found to be 65 16, and the aveage yield of all 435 F 3 lines was kg. What would be the expected gain fom selection if the F 3 families wee selected at the 10% level (i.e. discad 90% of families), and what would be the expected yield of these 43 selected lines at F 4, accoding to yield pefomance? Would you expect the same esponse to selection if the 43 selected F 4 families wee futhe selected fo yield the following yea? (Explain you answe). p (9) In chickpea beeding it is assumed that the coelation between yield pefomance of F 4 families in one yea and F 5 families in the following yea is F 4 beeding lines of chickpea wee evaluated fo seed yield in a popely designed field tial. All 4000 lines wee e-evaluated at the F 5 stage the following yea. If the highest yielding 10% wee selected based on F 4 pefomance and the highest yielding 15% wee selected based on thei F 5 pefomance, how many of the oiginal 4000 lines would you expect to be selected based on both F 4 and F 5 pefomance. Explain what Type I and Type II eo means in the context of selection. Estimate the Type I and Type II eos expected by selecting F 4 families fo yield at the 10% level and selecting F 5 families at the 15% level. (10) Paental selection can geneally be divided into two diffeent types. What ae these types and, biefly, indicate the diffeences between them. (11) Descibe the main featues of Noth Caolina I, Noth Caolina II and Diallel cossing designs. Explain the tems in the model fo the analysis of a diallel accoding to the method descibed by Giffing: Y g g s e ijk i j ij ijk and indicate the impotance of these tems and the use of Giffing Analysis in selecting supeio paental lines. (1) You have been appointed as Assistant Pofesso/Plant Beede in the Cops Division of McDonalds Univesity in Fysville, MD. It appeas that the beeding pogamme has been tying to select impoved genotypes with deceased suga content in the tubes. Howeve, in the 10 yeas pevious to you appointment, thee appeas to have been no genetic impovement esulting fom beeding. Outline thee easons that could individually, o in combination, have caused this lack of esponse. (13) In a seies of popely designed expeiments, a team of plant beedes poduced estimates of

19 naow-sense heitabilities ( h fo plant height and plant yield fom two diffeent n ) segegating families of sping baley (95.BAR.31 and 95.BAR.69). Both families wee gown on two fams (Moscow and Boise, in Idaho) in thee successive yeas (1993, 1994 and 1995). The h values fom each yea and site ae summaized below. n Chaacte Yea 95. BAR BAR. 69 Moscow Boise Moscow Boise Plant height Plant yield Which family is likely to give bette esponses in a beeding pogamme, given equivalent selection intensities, and why? In such a beeding pogamme, which of the two chaactes (plant height o plant yield) is likely to give the bette esponse to equivalent selection intensities, and why? Consistently highe aveage values of h n wee obtained at the fam nea Boise. Which site, if eithe, is likely to povide the moe accuate estimate of h, and why? The heitability estimates (paticulaly those fo plant height fo 95.BAR.69 in Moscow) vaied geatly ove the 3 yea peiod. What could be the cause? n (14) 4000 F 3 lentil beeding lines wee evaluated fo yield and the highest yielding 500 genotypes wee selected. The aveage yield of the 500 selections was 149 kg/ha while the aveage yield of the discad genotypes was 104 kg/ha. A andom sample fom the discads and the 500 selected lines wee gown in a popely designed F 4 tial whee the aveage yield of the andom genotypes was 1199 kg/ha and the yield of the selected 500 lines was 136 kg/ha. Detemine the naow-sense heitability fo yield at the F 3 of these lentil pogenies. (15) In a baley beeding pogamme fo high diastase powe it is known that the coelation between yield and diastatic powe is = In this beeding pogamme 3000 doubled haploids ae evaluated fo yield and diastatic powe in a popely designed field tial. If you wish to etain appoximately the best 150 lines what popotion would you discad based on yield and what popotion would you discad based on diastase powe to achieve this selected numbe? (16) In 1998, 10,000 F 3 head-ows wee gown in an uneplicated, but andomized, design fom Bobby Z s Wheat Beeding Pogam. At havest, seed fom all ows wee thashed and weighed. The aveage yield of all 10,000 lines was found to be kg. Afte weighing, 00 ows wee taken at andom and etained iespective of thei yield pefomance. Fom the emaining lines, the best 1000 ows fo yield wee selected fo futhe evaluation in the beeding scheme. The aveage yield of these selected lines was kg. In 1999, the bulk F 4

20 seed fom the 00 andom lines and the 1000 selected lines wee gown in a andomized complete block design. At havest, each plot was havested sepaately and the yield ecoded. Fom this 1999 tial it was found that the aveage yield of the selected lines was kg, while the aveage yield of the 00 andomly chosen lines was kg. Using the above infomation, detemine the naow-sense heitability fo yield in this mateial. Explain how this estimated value of heitability might influence you selection stategy fo futue F 3 headow selection stages. (17) In a Douglas fi beeding pogamme you have only sufficient esouces to sceen segegants fom two coss each yea. Howeve, in 1995, you have been povided data of family mean (MEAN), phenotypic vaiance (AR) and naow-sense heitability ( h ) fom each of six cosses. Fom these statistics detemine which two cosses you will concentate you effots in assuming that you will subsequently select at only the 10% level. Explain, biefly, you choices. Coss code MEAN AR h DF DF DF DF DF DF (18) 5 pogeny fom ten winte wheat cosses wee evaluated fo yield in a popely designed F 3 coss-pediction study unde field conditions. Fom the esults the following means and additive genetic standad deviations ( ) fo seed yields wee obtained fo each coss: A Mean A 9.WW WW WW WW WW WW WW WW WW

21 9.WW Also gown in the same tial wee five commecial cultivas. The aveage pefomance of the commecial cultivas was kg and the standad deviation was kg. Using univaiate coss pediction pocedues detemine which thee cosses should be used in beeding fo cultivas which would need to poduce yields: - Geate than the aveage of the contols plus one contol standad deviation - Geate than the aveage contol plus twice the contol standad deviation Rank you choices as fist, second and thid and include the pobabilities used fo you decision. (19) 500 dy pea F 6 beeding lines wee evaluated fo yield potential at two locations (Hillside and Nethetown). Afte havest and weighing, the 15% highest yielding lines wee selected at each location. When esults fom this selection wee examined it was found that 39 lines wee selected in the top 15% at each site. Fom this infomation, estimate the naow-sense heitability. In this same study, the following phenotypic vaiances and site means fo yield (ove all 500 F 6 lines) wee: Hillside Nethetown Phenotypic vaiance 96 kg 14 kg Site mean 7 kg 9 kg Given these data and the heitability estimated above, detemine the expected esponse to selection at 10% level. (0) Descibe the diffeence between geneal combining ability and specific combining ability. The following ae aveage plant heights (ove fou eplicates) of a 5 5 half diallel (including selfs) between sweet chey cultivas. Golden Gloy 11 Ealy Cimson 7 53 Sweet Delight Dwaf Evens Giant Red Golden Ealy Sweet Dwaf Giant Gloy Cimson Delight Evens Red

22 Estimate the geneal combing ability of each paent and calculate the specific combing ability of each coss. Which paents would be best in a beeding pogamme to develop cultivas with shot heights? (1) What is the diffeence between a cultiva with geneal envionmental adaptability and one with specific envionmental adaptability? Eight yellow mustad F 8 beeding lines wee gown at 0 locations thoughout the Pacific Nothwest egion. Significant genotype envionment inteactions wee detected fo yield by analysis of vaiance, and when a joint egession analysis caied out. The following ae line means and envionmental sensitivity (1+ ) values fom the analysis. Line 90.EW.34.5 Oveall Mean 134 Envionmental sensitivities JB JB HG HH AE HK Select the two best beeding lines which show geneal envionmental adaptability. Select the two best beeding lines which show specific envionmental adaptability. Chapte 8: Boadening the Genetic Basis (1) Unde what cicumstances would a plant beede choose use mutation beeding? () List two methods that have been used by plant beedes to induce inceased fequency of mutagens in plants. (3) List thee poblems that a plant beede may encounte when using mutagenesis in a beeding pogam. (4) What is possible with plant tansfomation (ecombinant DNA) techniques that is not possible with moe taditional beeding techniques.

23 (5) You have been asked to use ecombinant DNA techniques in you alfalfa beeding pogam to incease pofitability. Descibe all the pocesses you will have to complete to achieve this goal. (6) List thee vectos that have been used to tansfom plants with genes fom othe oganisms. (7) Biefly descibe two poblems that plant beedes may encounte in developing tansgenic cultivas. (8) Name fou types of mutation that can occu in plants and biefly descibe the featues of each type. Outline two difficulties that might be poblematic when using mutagenesis in a plant beeding pogamme. (9) Intespecific and integeneic hybidization can sometimes be useful techniques in plant beeding by intogession of chaactes and genes fom diffeent species. In an intespecific coss between Bassica napus and B. apa, thee was no evidence that any B. napus egg cells had been fetilized. List thee easons that could have caused this nonfetilization. Chapte 9: Contempoay Appoaches in Plant Beeding (1) List fou uses fo molecula makes in plant beeding. () Descibe any disadvantages of using molecula makes in plant beeding. (3) Descibe one difficulty that might be encounteed in utilizing QTL s in plant beeding selection.

24 (4) A coss is made between two paents in a hybid wheat beeding pogam, whee P 1 is the female paent and P is the male paent. When you un RFLP analysis you see gel pattens like those below. P 1 is the lane patten fo the female paent, P the male paent, and othe lanes (a though l) wee obseved fom a sample of seed F pogeny. F P 1 P a b c d e f g h i j k l Res Res Res Res Res Res Res a. Explain what could have caused the patten shown in lane f. b. It is known that Paent 1 has a single gene confeing esistance to yellow stip ust and F pogeny that poduced the bands, a, c, d, f, k, and l also showed esistance to yellow stipe ust. What can be detemined fom this (indicate on the figue above) and how could this be used in a plant beeding pogam. (5) Descibe thee applications involving tissue cultue o in vito plant popagation in a plant beeding scheme. Chapte 10: Pactical Consideations (1) You ae employed as baley beede fo a commecial company. At pesent the company does not have any geenhouse facilities. You ae tying to convince you pees that the beeding pogamme would benefit fom having a geenhouse: List five uses you would have fo a geenhouse in you beeding pogamme if one wee available. Geat job (we hope!) you have convinced the Boad of Diectos to poceed with puchasing a new geenhouse. List five featues you would like to equest to have in the new geenhouse facility. () Biefly descibe one poblem of using a geenhouse in a plant beeding pogam. (3) What is the pimay goal of conducting field evaluation tials in a plant beeding pogamme.

25 (4) List things to avoid when oganizing plant beeding field plots. (5) List two pactical poblems associated with off-station testing in plant beeding. (6) Why is expeimental design impotant in plant beeding evaluation tials? (7) List fou poblems that may be encounteed in oganizing and caying out off-station tials. (8) You have been employed as Senio Beede at the Hass Bean Beeding Co. fo seveal yeas and have had to cay out you beeding opeation with vey little funding. Due to a ecent takeove of the company by the Human Bean Seed Association, you have been given a vast sum of additional money. You have decided to spend this money upgading the compute facilities used by you beeding goup. To achieve this goal you have appointed a compute pogamme to develop a compute based plant beeding management. List the five main featues the compute package needs to pefom that would help incease the efficiency of beeding futue new cultivas.