Can. J. Plant Sci. Downloaded from by on 02/05/18. and over 3,000 seedlings that emerged most

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1 VARABLTY N FORAGE AND SEED PRODUCTON AND SEEDLNG GROWTH N ASTRAGALUS CCER S. SMOLAK and A. JOHNSTON Research Statin, Agriculture Canada, Lethbridge, AlbertaTlJ 48L Received9 Feb. 1976, accepted6 Apr Can. J. Plant Sci. Dwnladed frm by n 02/05/18 Fr persnal use nly. Srulrer, S. en JnNsrN, A Variability in frage and seed prductin and seedling grwth inastragalus cicer. Can. J. Plant Sci. 56l. 48'/-491. Frage and seed yield, percentage seed germinatin, speed f germinatin index, and 1,000-seed weight were determined fr a ppulatin f 170 plants selected frm Oxley cicer milkvetch (Astragalus cicer L.). Seedlings frm pen-pllinated seed frm the selected plants were measured fr leaf weight and leaf area, and specific leaf weight was calculated. Mst f the characters studied were asymmetrical in distributin. The crrelatin cefficient between frage and seed yields f mature plants was psitive and highly significant. Seedling leaf weight was psitively and clsely related t seedling leaf area, but seedling leaf area was a mre reliable indicatr f phtsynthetic efficiency. The variability in the characters studied in the selected ppulatin suggests that further imprvement in frage yield, germinatin percentage, speed f germinatin, and seedling vigr may be btained thrugh a breeding prgram. On a d6termind les rendements furrager et grainier, le purcentage de germinatin, 'indice de rapidit6 de germinatin et le pids de 1,000 grains sur 170 plants d'astragale pis chiche Oxley (Astragalus cicer L.). On a aussi 6tabli le pids, la densit6 et la surface fliaires des plantules btenues de semences prduites par pllinisatin libre. La distributin de la plupart des caractbres est asym6trique. Le cefficient de crr6latin entre le rendement furiager et le rendement grainier des plants matures est psitif et frtement significatif. Le pids fliaire des plantules mntre une crr6latin psitive 6trite avec la surface fliaire, mais ce dernier caractbre est un indicateur plus sffr de 'activit6 phtsynth6tique. La variabilit6 des caractdres 6tudi6s suggbre qu'n purrait par la s6lectin am6lirer le rendement furrager, le purcentage et la rapidit6 de germinatin, et la vigueur des plantules. Cicer milkvetch (Astragalus cicer L.), a Frage and seed prductin, as well as new frage legume, has a great ptential in seedling vigr, are imprtantcnsideratins range and pasture seeding. One cultivar, in the imprvement f cicer milkvetch. This Oxley, has been licensed fr use in Canada study was designed t determine the diver- (Jhnstn et al. l97 l). Seedling grwth f sity f sme characters assciated with Oxley is slwer than that f alfalfa (Smliak frage and seed prductin and with et al. 1972) and established stands start seedling grwth f Oxley cicer milkvetch, grwth abut 3 wk later in the spring and t investigate relatinships that culd (Jhnstn et al. 1975). As there is cnsider- lead t selectin prcedures based n able phentypic diversity fr agrnmic simple measurement criteria. characters in cicer milkvetch ppulatins (Twnsend 1970, 1971; Twnsend and MATERALS AND METHODS Ackerman 1975), imprvement in seedling Over 30,000 seeds f Oxley cicer milkvetch grwth shuld be pssible thrugh a breed- were germinated in vermiculite in plastic pans, ingprgram. and ver 3,000 seedlings that emerged mst rapidly were transplanted int flats in the greenhuse. At 3 m,,700 f the mst Can. J. Plant Sci (Juty 1976) 48't

2 488 CANADAN JOURNAL OF PLANT SCENCE Can. J. Plant Sci. Dwnladed frm by n 02/05/18 Fr persnal use nly. vigrus seedlings were transplanted int a spaced-plant nursery n irrigated land in spring 197r. The spaced-plant nursery was rated in 1972 fr earliness f grwth in the spring and fr erect grwth habit, and 170 plants were selected fr further study. When the seed reached maturity, the tp grwth f each selected plant was harvested and air-dried, and frage and seed yields were determined. The unscarified seed frm each selectin was allwed t germinate (fur replicatins f 25 seeds each) in paper twels placed in a germinatr at 21 C. Germinatin cunts were btained n the 3rd, 5th, 7th, loth, and 21st days, frm which a speed f germinatin index was calculated as described by Maguire (1962). Percentage germinatin reprted represents the ttal n the 2lst day. Average weight f 1,000-seed lt f each selectin was determined by weighing tw samples f 100 seeds. n additin, a secnd lt f seed frm each f the 170 plants was germinated and 25 seedlings per line were transplanted int flats in the greenhuse. At l0 wk, l0 seedlings, chsen at randm, frm each line were cut at grund level and the leaf area was measured by an electrnic leaf area meter. Leaf weight f each seedling was determined after ven-drying. Specific leaf weight (SLW) f each seedling was calculated as the rati f dry weight f leaves t the ttal leaf area (mg/cm2). Mean values f leaf area and weight and SLW were used in further analysis. Frequency distributins were prepared fr each f the characters studied. Tests fr skewness (Snedecr 1956) were made t determine whether the ppulatin sampled represented a symmetric6l distributin. The prbability f selecting superir plants is greater in a skewed distributin than in a nrmal ppulatin, prvided the tw ppulatins have the same mean and variance. Simple crrelatin cefficients between all pairs f characters were calculated. RESULTS AND DSCUSSON Mst f the characteristics studied in the selected ppulatin had an asymmetrical frequency distributin (Fig. l). Frage yield, percentage germinatin, speed f germinatin index, seedling leaf area, and SLW had skewness values that were significantly different frm nrmal (Table l). The best 107 f the plants in each f the histgrams had frage yields f ver 1,440 g, percent germinatin f ver 60.0, speed f germinatin index f r higher, a seedling leaf area f ver 95.6 cmz, r SLW values f ver l), indicating that superir plants were present in the existing selected ppulatin. Crrelatin cefficients amng the characters shwed sme imprtant relatinships (Table 2). The relatinships between frage and seed yield, seed yield and speed f germinatin index, speed f germinatin index and percentage germinatin, and seedling leaf area and leaf weight were psitive and significant (P < 0.01), but nly the latter tw were f high predictive value. SLW 1mg/cm2) was negatively, but significantly (P < 0.01), crrelated with leaf area. The relatinships between percentage germinatin and seed yield, SLW and seedling leaf weight, and seedling leaf weight and frage yield were als psitive and significant (P < 0.05). Table. Statistics fr eight characters measured n 70 selected cicer milkvetch plants Character Mean Range SD Skewness t value Frage yield (g/plant) Seed yield (g/plant) q germinalin Speed f germinatin index l,0ogseed wt (g) Seedling leaf area (cmz) Seedling leaf wt (mg) SLW (mg/cm'z), U '7 5'17.U2,055.O 27.O O ' r t ** ** *x ** * *Significantly different frm nrmal atthe 57 level f prbability' x*significantly different frm nrmal at the 7 level f prbability.

3 SMOLAK AND JOHNSTON-POTENTAL OF ASTRAGALUS CCER 489 Can. J. Plant Sci. Dwnladed frm by n 02/05/18 Fr persnal use nly. b r d v) 6i a 6 F 4 9ii3tr (t) ='11 - d C- Ee hg (t)!'=: n j.ri: 6L! E,9.: d = de! x E d-b ** * :,.j.:.- ttl ** \n x* l \ NO\O *: d * qeeq ttl O\c)c \ + *NOO*O i A::: ^' ** \*N-r\ s--r- ^ d.=de 3s59H;;.Qc tr lfhq ;.8 8B -e -s! g Eb 3 gg' ^=E-=== T.E H.g.EE g. U)a)U)-ah.a xx q ss P9 d 6.s.s v) cn **

4 Can. J. Plant Sci. Dwnladed frm by n 02/05/18 Fr persnal use nly. 490 r ::[f CANADAN JOURNAL OF PLANT SCENCE ::[ c r2s t50? ta5 220 FRAE Y ELD (c/drr) see YEL ll9lnt),1l** eeacerreeerrrnarrn! i=[[ *t'"''''' t.]lt ':F 6EEOLTtG(LEAF WETOHT Fig. l. Histgrams f sme characters in 170 cicer milkvetch plants. Weight f 1,000 seeds was apparently nt related t any f the ther parameters measured. Twnsend (1972) has shwn sme assciatin between seed size and seedling emergence, and has suggested that it may be pssible t increase seedling vigr by selecting fr increased seed size, but Carletn and Cper (1972) cncluded that differences in seed size due t differences between plants may be crrelated with seedling perfrmance in sme species, but nt in thers, while differences in seed size within plants are highly crrelated with seedling perfrmance. n ur study, there was n crrelatin between seedling leaf area and frage yield, seed yield, percentage germinatin, r speed f germinatin, nr was seedling leaf weight related t seed yield, percentage germinatin r speed f germinatin. SLW was related nly t its cmpnents, seedling leaf area and weight. a c a r3.5 ta 25.7 SPEED OF G RMNA'ON ND X ld SPECFC LEAF WEGHT n /ci?l Seedling leaf area was mre clsely assciated with SLW than was seedling leaf weight; therefre seedling leaf area culd be used as an indicatr f phtsynthetic efficiency f cicer milkvetch. Pearce et al. (1969) suggested the pssibility f increasing phtsynthetic efficiency and yield ptential f alfalfa by selecting fr high SLW in a breeding prgram. Seedling weight has been used as a criterin fr screening prgeny lines fr seedling vigr in sme legumes. The assciatin between fraqe and seed yield indicates that many f the [igh frageyielding plants had high seed yields; therefre selectin can be cncentrated n frage yield. The variability in the characters studied within the selected ppulatin f Oxley cicer milkvetch indicates that imprvement in yield ptential and in seedling vigr culd be expected frm a breeding prgram. Twnsend (1970) has shwn that variability in sme characters in 20 accessins f cicer milkvetch was f sufficient magnitude t suggest imprvement, and in a later study (Twnsend l97l) suggested that because f relatively lw assciatins between sme f the characters studied, it shuld be pssible t select fr several cmbinatins f characters. Even with sme selectin, there was cnsiderable variatin fr mst characters in ur study. This means that in an unselected r randm ppulatin f Oxley, the variability wuld have been much greater. Selectin fr imprvement in the ppulatin studied is pssible fr frage yield, percentage germinatin, speed f germinatin, seedling leaf area, and specific leaf weight. CARLETON, A. E., and COOPER, C. S Seed size effects upn seedling vigr f three frage legumes. Crp Sci. 12: JOHNSTON, A., SMOLAK, S., HANNA, M. R. and HRONAKA, R Cicer milkvetch fr western Canada. Can. Agric. Publ l6 pp. JOHNSTON, A., SMOLAK, S., HRONAKA, R. and HANNA, M. R Oxley cicer milkvetch. Can. J. Plant Sci. 5l:

5 SMOLAK AND JOHNSTON-POTENTAL OF ASTRAGALUS CCER 491 Can. J. Plant Sci. Dwnladed frm by n 02/05/18 Fr persnal use nly. MAGURE, J. D Speed f germinatin Aid in selectin and evaluatin fr seedling - emergence and vigr. Crp Sci. 2: PEARCE, R. B., CARLSON, G. E., BARNES, D. K., HART, R. H. and HANSON, C. H Specific leaf weight and phtsynthesis in alfalfa. Crp Sci. 9: SMOLAK. S.. JOHNSTON. A. and HANNA. M. R Germinatin and seedling grwth f alfalfa, sainfin and cicer milkvetch. Can. J. Plant Sci. 52: SNEDECOR, G. W Statistical methds. wa State University Press, Ames, wa. 534 pp. TOWNSEND, C. E. 19'70. Phentypic diversity fr agrnmic characters in Astragalus cicer L. CrpSci. lo: TOWNSEND, C. E Assciatin amng characters related t seed prductin in lstragalus cicer L. Crp Sci. 11: TOWNSEND, C. E nfluence f seed size and depth f planting n seedling emergence f tw milkvetch species. Agrn. J.64: TOWNSEND, C. E. and ACKERMAN, W. D Variability fr vigr, height, and flwering in intrductins f cicer milkvetch. Can. J. Plant Sci. 55:

6 Can. J. Plant Sci. Dwnladed frm by n 02/05/18 Fr persnal use nly. This article has been cited by: 1. C.E. Twnsend. Breeding, Physilgy, Culture, and Utilizatin f Cicer Milkvetch (Astragalus cicer L.) [Crssref]