Effect of Phenologic and Leaf Morphologic Characteristics of New Maize Hybrids in Drought Stress

Transcription

1 International Research Journal of Applied and Basic Sciences 2012 Available online at ISSN X / Vole, 3 (9): Science Explorer Publications Effect of Phenologic and Morphologic Characteristics of New Maize Hybrids in Drought Stress Maryam Hajibabaei 1*, Farhad Azizi 2 1- Yong Researchers Club, Varamin- Pishva Branch, Islamic Azad University, Varamin, Iran 2- Seed and Plant Research Institute, Karaj, Iran *Corresponding Author Hajibabaee_m@yahoo.com Abstract In order to study the effects of drought stress on phenologic and leaf morphologic characteristics and different characters such as yield of fourteen new forage corn hybrids, an experiment was conducted at Seed and Plant Improvement Institute, Karaj, Iran in The experiment was carried out using split-plot in a randomized complete block design with three replications. The main plots consisted of three irrigation regimes (irrigation after 70, 100 and 130 mm cumulative evaporation from standard evaporation pan class A) and subplots included 14 new forage maize hybrids. In this experiment Kernel yield per hectare, days to pollination, days to silk, Anthesis-silking interval, ear per plant, Ear leaf chlorophyll, rolling and senescence were considered. The results showed that hybrids differences in terms of days to pollination, days to silk and Anthesis-silking interval were significantly different (P<0.01). But the interaction of hybrids and irrigation regimes was not significant for all of the traits. Therefore hybrids represent the same reaction to the irrigation regimes. Drought stress was significant for all the traits except number of ear per plant. Severe stress decreases dry yield for 32% percent in contrast with control. Keywords: Maize, drought stress, hybrid, kernel yield, leaf chlorophyll. Introduction The effects of water deficit are the main factor limiting maize (Zea mays L.) production in arid and semiarid regions. Forage maize is an important crop as to silage the whole harvested plant (Coors, 1995). Khalily et al, (2010) reported that in drought stress condition, tolerant hybrids should be select based on anthesis silking interval, days to silk, and the number of kernels per ear row. The effects of drought on yield of crops depend on their severity and the stage of plant growth during which they occur. Lauer and Cussicunqui (1997) stated that the most effective energy factor of silage maize is the grain to forage ratio. Grains contain a large amount of highly digestible starch (Roth and Lauer, 1997), more protein and lower levels of cell wall carbohydrate and higher digestibility (Coors, 1995). Grains energy is 80% higher than forages. Roth and Lauer (1997) reported that most hybrids with a high ratio of grain to forage are suitable and are recommended. Song and Dai (2000) studied the effect of drought stress on corn growth and development and reported that drought stress prevents the growth and development of corn female flowers. Also height, diameter, dry and fresh weight were reduced by water deficit. Cakir (2004) reported that water stress during different corn growth stages decreases yield in different degrees of intensity. The decrease of yield depends on both stress severity and plant growth stage. Rezaverdinejad et al, (2006) by applying low irrigation treatments at different growth stages of forage corn in Karaj (Iran) reported that drought stress at vegetative and flowering stages compared to normal irrigation reduced yield by 28% and 29% respectively. Pandey et al, (2000) reported that deficit irrigation at early vegetative growth, slightly decrease leaf area index, plant height, plant growth rate and dry matter in corn. In order to study the effect of drought stress on physiologic characteristics and chlorophyll and yield in 14 new maize (Zea mays L.) hybrids, an experiment was conducted at Seed and Plant Improvement Institute Karaj, Iran in 2009.

2 Materials and Methods This experiment was conducted at Seed and Plant Improvement Institute Karaj, Iran in The soil texture of the research site was loam-clay with ph 7.5 and the Electrical Capacity (EC) was 0.7 dsm -1. The statistical design was a split-plot layout in randomized complete block design with three replications. In this study three levels of irrigation were considered as main factor, including S1 = normal irrigation, S2 = mild stress and S3 = severe stress (irrigation after 70, 100 and 130 mm evaporation from Class A evaporation pan respectively). 14 corn hybrids were designated in sub plots as it mentioned in Table 1. Cultivation pattern in each plot was 3 lines each 7m in length and seeds were cultivated 75cm (75000 plant/ha) apart on the lines. In order to prevent irrigation confliction, two rows at the beginning and end of each main plot was considered as marginal rows and were not cultivated. Amount of fertilizer application was based on soil test. 400 kg/ha urea in two stage : before cultivation and at 6-7 leaf stage. Irrigation time was determined using daily evaporation rate of class A evaporation pan. Volume of water for irrigation was determined using formula H= b (θ F.C - θ m ) D and V= H A.Where H is the water height in the plot, b is soil bulk density, θ F.C is the moisture level at field capacity, θ m is plot moisture at irrigation time, D is the root development depth, V is the volume of irrigation water in the plot, and A is the plot area. Number Table 1. Name and code numbers of 14 corn hybrids Hybrids 1 K47/ MO17 2 K3653/2 K19 3 K3653/2 MO17 4 KSC700 5 KSC704 6 KSC720 7 KLM76004/ K3545/6 8 K74/ K3545/6 9 K47/ K3544/1 10 KL M76004/ K3544/1 11 K47/ K3544/1 12 K47/ MO17 13 KLM77029/ MO17 14 KLM76005/ MO17 From each plot 10 plants were randomly selected to measuring the traits such as Kernel yield per hectare, ear per plant, Ear leaf chlorophyll, rolling and senescence. SAS software version 9.1 was used for statistical analysis and Duncan multiple range test was used for means comparison. Results and Discussion days to pollination Evaluation of number of days to pollination showed significant difference for various irrigation regimes and hybrids (P<0.01) but the interaction between irrigation and hybrids did not show any significant difference (Table 2). This indicates that the hybrids used in this study showed similar reaction to the stress conditions. Mean comparison of different irrigation regimes showed that water deficit stress caused delay in pollination. (Table 3). Effect of drought stress on days to pollination in maize investigated by Jaafari and Imani (2004. Hybrids mean comparison (Table 4) showed that the highest number of days to pollination was observed in hybrids 4 and 6 (70 days) while hybrid 2 and 10 had the lowest number of days (64 days). days to silk Significant difference (P<0.01) was observed for number of days to silk among the various irrigation regimes and hybrids, while the interaction between different irrigation treatments and hybrids did not show any significant differences (Table 2). Mean comparison of irrigation regimes indicated that silk in irrigation after 70 and 130 ml was about 2 days higher than irrigation after 100 ml evaporation (Table 3). Lauer (2003), Traore et al, (2000), Stone (2001), Budiarti (1997) and Saeed et al, (1997) reported delay in silk in drought stress in maize. Later silk in drought stress

3 conditions also reported by Westgate and Boyer (1986). Means comparison of hybrids showed that hybrid number 6 had the highest number of days to silk (74.77 day) and hybrid 2 had the lowest (68.33 day) (Table 4). Anthesis-silking interval According to Table 2, various irrigation regimes and hybrids showed significant difference (P<0.01) for Anthesis-silking interval. But the interaction between irrigation regimes and hybrids were not significant. Means comparison of irrigation regimes indicated that there was significant difference between 70 and 130 ml evaporation. Low content of water soil in flowering stage caused delay in silk and their growth disorders, so Anthesis-silking interval increased in water deficit stress greatly (Table 3). Delay in silk which resulted in non-simultaneous of pollination and silking. Therefore reduction in kernel yield, are the main effects of drought stress in flowering stage. This result supported the works of Bolanos and Martinaz, 1993; Bolanos and Edemedes, 1996; Abrecht and Carberry, 1991; Grant et al., Means comparison of hybrids (Table 4) showed that the highest and lowest Anthesis-silking interval were obtained in hybrids 13 (4 days) and 7 (2 days) respectively. ear per plant Different between irrigation treatments, hybrids and also interaction between irrigation treatments and hybrids on number of ear per plant were not significant (Table 2). Means comparison for irrigation regimes showed that from irrigation after 70 to 100 mm evaporation number of ear per plant significantly decreased (Table 3). According to Table 4, hybrids number 4 and 13 and 14 had the highest number of ear per plant and hybrid number 10 had the lowest. Ear leaf chlorophyll Effect of different irrigation treatments on ear leaf chlorophyll showed a significant difference (P<0.01) while hybrids in ear leaf chlorophyll a significant difference (P<0.05). but the interaction between irrigation and hybrids were not significant (Table 2). Mean comparison of different irrigation treatments showed that from irrigation after 70 to 100 mm of evaporation significantly decreased leaf chlorophyll, while although irrigation after 100 mm to 130 mm evaporation also reduced leaf chlorophyll but was not significant (Table 3). Water deficiency causes pigment and plastid damage. Drought stress decrease chlorophyll and carotenoids (Duysen and Freman, 1975). Plant reaction aspect of total chlorophyll content in drought stress with flag leaf reaction, which normally senescence later than other leaves, is better character than chlorophyll concentration of an especial leaf (flag leaf) in effect of drought stress on source (Sio- Se Mardeh et al., 2006). Mean comparison of hybrids (Table 4) showed that the highest and lowest leaf chlorophyll levels were obtained in hybrids 2 and 11 (38.612) and 4 (28.885) respectively. roling and senescence Significant difference (P<0.01) was observed for leaf rolling and leaf senescence among the different irrigation while effects of hybrids treatments and the interaction between different irrigation treatments and hybrids did not show any significant diference (Table 2). Mean comparison of irrigation regimes indicated significant difference in leaf roling (Table 3) and sever drought stress treatment had the highest effect on leaf roling (5.381). Because of decreasing the accumulated energy and respiration of leaf, sometimes leaf roling is one of the mechanisms of avoiding stress. Therefore, reduction in growth, yield and leaf area which resulted of water limitation, depend on the speed of leaf extending. So, more soil humidity affects the photosynthesis and making of primary substrates. Increasing in maize seed yield correlated with leaf photosynthesis and soil humidity (Blum, 1997). Drought stress caused reduction in leaf area, following of acceleration in leaf senescence, and biomass accumulation, actually. In other words, accelerating in leaf senescence, caused reduction or elimination of assimilation by leaves and reduction of kernel yield (Zinselmeier et al., 1995). According to Table 4, hybrids number 3 and 14 had the highest leaf senescence (2.667 and respectively) and hybrid number 10 had the lowest (1.722). Kernel Yield The results indicated that there was significant difference (p<0.01) between irrigation regimes (Table 2). No significant difference for interaction between irrigation regimes and hybrids was observed which emphasized the same reaction of the hybrids in stress conditions. Mean comparison of irrigation regimes showed that the most kernel yield (13699 kg. ha -1 ) obtained in normal irrigation. In S2 and S3 treatments, kernel yield decreased to 21% (10806 kg. ha -1 ) and 32% (9350 kg. ha -1 ) in comparison to normal irrigation (Table 3). Significant reduction of kernel yield was done due to decreasing in the number of kernels per ear and 1000-kernels weight. This result was in agreement with (Denmead and Show, 1960). Regarding the kernel yield as accumulated dry matter product, decrease of dry matter in stress conditions could result in decrease of kernel yield. Herrero and Johnson (1981) suggested that highest susceptibility of corn to drought

4 stress occurred in fertility and improvement of floret stage which caused decrease in yield. Also, drought stress in flowering stage causes non-simultaneous ear and tassel, increase ASI and finally reduction of kernel yield. Reduction of kernel yield in drought stress condition also reported by (Song and! "# yield (12961 kg. ha -1 ) and the hybrid 9 had the least kernel yield (10214 kg. ha -1 ) (Table 4). Conclusion In this experiment the hybrid 4 (KSC700) had the maximum kernel yield (12961 kg.ha -1 ) and number of days until the (70 day) and number of ear per plant (0.94) and hybrid 2 (K3653/2 K19) had the maximum highest leaf roling (3.778) and highest ear leaf chlorophyll (44.631) were the best hybrids. Correlations According to traits correlations (Table 5) kernel yield are significantly correlated with most other traits. roling and leaf senescence had a significant negative correlation with ear leaf chlorophyll. Ear leaf chlorophyll also showed highly significant correlation with all traits except number of days until silk. roling showed a highly significant positive correlation with all other traits except leaf senescence. Kernel yield had a significant positive correlation with number of days until the pollination and number of days until silk. According to traits correlation table (Table 5) it can be concluded that ear leaf chlorophyll, leaf roling, leaf senescence, number of days until the, number of days until silk, Anthesis-silking interval can impact kernel yield under deficient soil moisture conditions. Therefore by breeding hybrids for these traits, crop performance reduction can be largely avoided under drought condition.

5 Table 2. Analysis of variance for some traits of new maize hybrids under three irrigation regimes S.O.V Replication Irrigation E(a) Hybrid H*I E(b) CV (%) df Kernel yield ns ** ns ns days until the ns ** ** ns days until silk ** ** ** ns Anthesis-silking interval ns ** ** ns number of ear per plant ns ns ns ns Ear leaf chlorophyll ns ** * ns roling * ** ns ns senescenc e ns ** ns ns ns, * and ** : Non significant, significant at P<0.05 and P<0.01 respectively. Table 3. Means Comparison of three irrigation regimes Irrigation treatments Kernel yield (kg.ha -1 ) days until the days until silk Anthesissilking interval number of ear per plant Ear leaf chlorophyll roling senescen ce irrigation after 70 mm of evaporation a c a b a a c b irrigation after 100 mm of evaporation irrigation after 130 mm of evaporation b b b b ab b c a a a b b Means with the same letter in each column have no significant difference (P<0.05) b a a a

6 Table 4. Means Comparison for 14 new maize hybrids Hybrid Kernel yield (kg.ha -1 ) days until the days until silk Anthesissilking interval number of ear per plant Ear leaf chlorophyll roling senescence ab 69 abcd b cde ab abc a ab ab 64 f e abcde ab a a 2 ab ab cde bc abcde ab cd 5 a a a 70 a b de a d a ab ab bcde bc abc ab abc a ab ab a a abc ab cd a ab ab ab bc e ab cd a ab ab abc b abcde ab bcd a ab b ef de abcde ab cd a ab ab ab f de de bc abcd ab b ab abcd ab a a b ab ab de cd bcde ab cd a ab ab bcde bc a a cd a ab ab bcde bc abc a cd a a Means with the same letter in each column have no significant difference (P<0.05).

7 Table 5. Traits correlation coefficients roling senescence Ear leaf chlorophyll ** ** roling 0.44 ** senescence days until the days until silk Anthesissilking interval days until the days until silk Anthesis-silking interval Kernel yield ** ** 0.02 ns 0.50 ** ns ns ns ns ns ns ns 0.30 ns 0.84 ** ** ** 0.26 ** ** ns ns, * and ** : Non significant, significant at P<0.05 and P<0.01 respectively References Abrecht DG, Carberry PS The influence of water deficit prior tassel initiation on maize growth. Field Crops Res., 31: Blum A Cnstitutive traits affecting plant performance under stress. In: Edmeads GO, Banziger M, Micelson HR,. pena- Valdiva (eds). Developining drought and low tolerant in maize, Proc Symp. CYMMYT, Elbatan. pp Bolanos J, Edemedes GO The importance of the anthesis silking interval inbreeding for drought. Tolerance in tropical maize. Field Crops. Res. 48: Bolanos J, Martinaz L Eight cycles of selection for drought tolerance in low land tropical maize. Responses in drought adaptive physiological and morphological trait. Field Crop Res. 31: Budiarti SG Green house and field test of maize varieties for drought tolerance. Simposioum Nasional dan Kongres. PERIPI (Indonesia) Cakir R Effect of water stress at different development stages on vegetative and reproductive growth of corn. Field Crops Res. 89:1-16. Coors JG Grain yield and nutritional quality of corn silage. Final 4 year UW corn silage research consortium meeting Madison. WS unpublished. Denmead OT, Show RH The effect of soil moisture stress at different stages of growth on the development and yield of corn. Agronomy Journal.52: Duysen ME, Freman TP Partial restoration of the high rate of plastid pigment development and the ultra culture of platis in detached water stressed what leaves. Plant physiology, 55: Grant RF, Jackson BS, Kiniry JR, Arkian GF Water deficit timing effects on yield componentsin maize.agron. J. 81: Herrero MP, Johnson RR Drought stress and its effects on maize reproductive system. Crop sci. 21: Jaafari P, Imani MR Study of drought stress and plant density on yield and some agronomical traits of maize KSC 301. Abstracts of the 8th. Iranian Congress of Crop Sciences. College of Agriculture, Universty of Guilan, Rasht, Iran. Page 235 (in Farsi). Khalily M, Moghaddam M, Kanouni H, Asheri E Dissection of drought stress as a grain production constraint of maize in Iran, Asian journal of crop science2 (2): 60-69, issn Lauer J What happens with in the corn plant when drought occurs. Wisconsin Crop Manager. 10(22): Lauer J, Cussicunqui J How thick should I plant my corn? Field Crops, 28:5-15pp. Pandey RK, Maranville JW, Chetima MM Deficit irrigation and nitrogen effects on maize in a Sahelian environment. II. Shoot growth. Agric. Water Manage. 46: Rezaverdinejad V, Sohrabi T, Liaghat AM Study of deficit irrigation effect on corn forage yield at its growth stage.1 th national congress of irrigation and drainage nets. Ahvaz. Roth GW, Lauer JG Agronomist s perspective of corn hybrids for silage. Silage: Field to Feed bunk North American Conference. Ithaca, NY, Northeast Regional. Agricultural Engineering Service, pp:

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