Estimation of quantitative genetic parameters for grain yield and quality in winter wheat under high and low nitrogen fertilization

The main question connected with developing wheat cultivars adapted to low nitrogen (N) is whether separate breeding programs for low and high input conditions are necessary. Nineteen wheat cultivars were grown over three years in Croatia in a total of eight environments at high N and low N in order to determine the effect of two N levels on means, variances and heritability of grain yield and bread-making quality and to assess the relative efficiency of indirect selection under high N in improving trait means under low N. Means of grain yield and grain protein content decreased under low N 10 and 13 %, respectively compared to the high N, whereas higher reductions of means due to lower fertilization were observed for grain N yield (21 %), wet gluten content (20 %), Zeleny sedimentation value (27 %) and for most rheological parameters, whose mean values were reduced from 20 % to as much as 57 %. Heritabilities for grain yield and grain N yield at high N were 0.82 and 0.76, respectively, and 0.77 and 0.43 at low N. Heritability for dough development time, stability and resistance also tended to be higher at high N than at low N due to a decrease in genetic variance and an increase in error variance at low N. The genetic correlation coefficients between high and low N were higher than 0.90 and the efficiency of indirect selection under high N for performance under low N was near 1.0 for grain yield and for most bread-making quality traits.     

小麦花培品质育种各世代的品质参数分析

通过对冬小麦花培1代至花培5代的品质测试,研究了花培品质育种的品质测试的世代程序和有效性。结果表明,品质性状在花培早代已趋于稳定,高分子量谷蛋白亚基组成从H1起就稳定遗传,115对H1与H2材料和62对H2与H3材料的籽粒蛋白质含量、硬度和沉降值具有高度相关性,且籽粒蛋白质含量和SDS沉降值H2与H3世代间差异不显著。对中选的京单00-594的H4和H5世代进一步品质测定结果表明,通过花培早代选出的优质材料是可靠的,其优质性状能稳定遗传。研究提出了花培品质育种各世代品质测试的程序,证明了花药培养结合早代品质测试,是一条快速、有效的小麦品质育种途径。     

杂交粳稻亲本米质性状优异配合力的标记基因型鉴定

杂交粳稻米质整体水平不如常规粳稻也是限制杂交粳稻广泛种植的原因之一。本研究选用115个SSR引物扩增6个粳稻BT型不育系和12个恢复系的标记基因型,并分析72个F₁组合谷粒长、谷粒宽、糙米率、精米率、整精米率、垩白米率、垩白度、糊化温度、胶稠度和直链淀粉含量10个米质性状的配合力,结合亲本SSR分子标记数据和性状配合力数据筛选了10个米质性状优异配合力的标记基因型。结果共鉴定出30个SSR标记基因型与亲本10个米质性状配合力显著相关,其中25个与亲本米质性状不良配合力相关,5个与优异配合力相关。标记基因型RM263-175/180和RM444-230/240可以使F₁整精米率分别提高3.2%和2.5%。RM3-120/150可以使F₁谷粒长缩短2.4%,RM444-180/240可以使F₁谷粒宽增加2.1%。RM428-273/294可以使F₁植株上的杂交稻米直链淀粉含量减少7.0%。有8个标记基因型同时也影响产量性状配合力。RM3-120/150同时可以使F₁的每穗总粒数和每穗实粒数分别增加15.9%和10.9%。RM1211-150/160可使F₁的糙米率和精米率分别减少0.9%和1.1%,同时使F₁的每穗总粒数和每穗实粒数分别增加21.8.%和20.4%。RM23-150/160可使F₁的垩白米粒率和垩白度分别增加44.1%和45.7%,同时使F₁的单株日产量和每穗总粒数分别增加11.2%和11.6%。这些结果可用于指导亲本米质性状和产量性状配合力的分子标记辅助改良以及未来杂交粳稻组合配置中的亲本选配。     

Effects of Mediterranean climate on wheat bread-making quality

The unpredictability of the Mediterranean climate causes a large fluctuation in wheat yield and quality but offers the opportunity for the production of high quality wheats which are lacking in the European Union.

This paper describes the effects of nitrogen fertilization rate and timing on five Triticum aestivum L. cultivars differing in bread-making quality, cultivated in six representative Italian sites (years/locations). Nitrogen was applied at each location at two rates, the first corresponding to the amount estimated to maximize grain yield, the second 30% higher. Three timings of nitrogen applications were tested including a late application at the boot stage. Bread-making quality was evaluated with the Chopin alveograph and each sample was assigned to the following qualitative classes of the Italian market: Class 1, improver wheat; Class 2, for direct bread-making; Class 3, ordinary wheat.

Cultivars differed significantly in all agronomic and qualitative traits. Grain yield was highest in the northern location (7.1 t ha⁻¹) and lowest in the south of the Italian peninsula (2.61 ha⁻¹), while in Sicily abundant rains in both years enabled a yield of 6.41 ha⁻¹ to be obtained. As far as bread-making quality is concerned, the greatest proportion of grain samples belonging to Class 1 was obtained from the northern location. The year of cultivation strongly affected quality, particularly with regard to gluten tenacity, in all locations, though the quality ranking of the cultivars remained substantially stable across locations. Nitrogen applications greater than those considered optimal to maximize yield, combined with a better distribution during the life cycle, significantly improved bread-making quality.

It was concluded that high quality wheats can be obtained in a wide range of growing conditions in the Mediterranean climate. However the likelihood of genotype × environment interactions, statistically significant for both yield and quality, call for a more precise management of nitrogen fertilization in relation to the cultivars chosen and the climatic features of each site.     

Selection for high spike fertility index increases genetic progress in grain yield and stability in bread wheat

Spike fertility index (SF) has been proposed as a promising trait to be used as a selection criterion in wheat breeding programs aimed at increasing grain yield, but no actual evidence of its successful application has been reported. In this study, 146 recombinant inbred lines derived from a cross between ‘Baguette 10’ and ‘Klein Chajá’, Argentinean spring bread wheat cultivars with contrasting SF, were evaluated during three crop seasons (2013, 2014 and 2015) at Balcarce, Argentina. Grain yield, grain number/m², grain weight, and SF were measured at maturity. Changes in grain yield (i.e., responses to selection) after application of different selection strategies, including different selection criteria and selection intensities, were determined. Significant correlations were observed between grain number and grain yield, SF and grain yield, and SF and grain weight. Analysis of SF variance components showed a significant genotype?×?environment interaction, but it represented only 9% of the total variation, whereas 51% of the variation was genetic, resulting in a high narrow-sense heritability (0.84). The use of SF as a selection criterion, either solely or in combination with selection for high yield, increased yield, resulting in higher and more stable yields than if selecting for high yield alone. Our findings support the use of spike fertility index as a selection criterion for increasing genetic progress and stability of yield in bread wheat breeding programs.     

Identifying high yielding stable winter wheat genotypes for irrigated environments in Central and West Asia

Improved winter wheat (Triticum aestivum L.) cultivars are needed for the diverse environments in Central and West Asia to improve rural livelihoods. This study was conducted to determine the performance of elite winter wheat breeding lines developed by the International Winter Wheat Improvement Program (IWWIP), to analyze their stability across diverse environments, and to identify superior genotypes that could be valuable for winter wheat improvement or varietal release. One hundred and one advanced winter wheat breeding lines and four check cultivars were tested over a 5-year period (2004–2008). Grain yield and agronomic traits were analyzed. Stability and genotypic superiority for grain yield were determined using genotype and genotype × environment (GGE) biplot analysis. The experimental genotypes showed high levels of grain yield in each year, with mean values ranging from 3.9 to 6.7 t ha⁻¹. A set of 25 experimental genotypes was identified. These were either equal or superior to the best check based on their high mean yield and stability across environments as assessed by the GGE biplot analysis. The more stable high yielding genotypes were ID800994.W/Falke, Agri/Nac//Attila, ID800994W/Vee//F900K/3/Pony/Opata, AU//YT542/N10B/3/II8260/4/JI/Hys/5/Yunnat Esskiy/6/KS82W409/Spn and F130-L-1-12/MV12. The superior genotypes also had acceptable maturity, plant height and 1,000-kernel weight. Among the superior lines, Agri/Nac//Attila and Shark/F4105W2.1 have already been proposed for release in Kyrgyzstan and Georgia, respectively. The findings provide information on wide adaptation of the internationally important winter wheat genotypes, and demonstrate that the IWWIP program is enriching the germplasm base in the region with superior winter wheat genotypes to the benefit of national and international winter wheat improvement programs.     

小麦抗麦红吸浆虫基因标记的开发与验证

麦红吸浆虫(SitodiplosismosellanaGéhin)严重影响小麦产量和品质,选育和使用抗虫品种是降低虫害损失最安全有效的途径,利用抗虫性连锁或功能标记对提高小麦抗虫分子育种效率具有重要意义。在前期从转录组数据中挖掘到抗虫性主效QTL (QSm.hbau-4A) 6个相关差异基因的基础上,依据这些基因序列中存在的InDel和SNP,分别开发了2个EST标记和6个KASP标记,并在抗虫性不同的一套重组近交系(RIL)和一套小麦品种中进行了标记的有效性验证。所开发的8个标记在抗、感虫小麦亲本间均表现出较好的多态性,在RIL株系中的检测有效率均达到90%左右;除E10-10外,这些标记在供试高抗(56.3%～86.7%)和高感(85.7%～100.0%)小麦品种中的检测有效率均较高,可用于小麦种质资源的抗虫性筛选。同时发现, 11个具备所有抗虫标记位点的抗虫小麦品种,多为审定时间较早或已停止使用的品种,这使得结合标记辅助选择等手段鉴定和创新小麦抗虫种质资源的工作日益紧迫。     

Farmer participatory evaluation confirms higher grain yields in spring wheat using a selection index for spot blotch resistance, maturity and kernel weight

Wheat (Triticum aestivum L.) cultivars for the warm regions of South Asia must produce high yields and possess resistance to spot blotch (Cochliobolus sativus), early maturity and high kernel weight. A study was conducted to determine the effectiveness of selecting for high grain yield based on a selection index for spot blotch resistance, maturity and kernel weight in four wheat crosses involving a susceptible cultivar and resistant genotypes. Initial selection of 40 progeny lines in each cross had been made using a selection index based on disease severity, days to heading and kernel weight as reported by Sharma and Duveiller [{Crop Sci 43 (2003) 2031}]. The five highest grain-yielding progeny lines from among the 40 lines in each cross, their parents and five popular commercial cultivars were evaluated in field trials at two sites in Nepal in the 2002 and 2003 wheat seasons. Multiple spot blotch assessments were made to determine the area under disease progress curve (AUDPC). Grain yield, thousand-kernel weight (TKW), days to heading and plant height were examined. The wheat genotypes in the farmer's field were also ranked on the basis of cultivar preference criteria by the local farmers. The 20 progeny lines always showed a higher (+11 to +125%) grain yield and heavier (+10 to +44%) kernels than their parents and a lower (−83 to −89%) AUDPC than the susceptible parent. The progeny lines showed 98–100% grain yield, 97–100% TKW and 66–78% AUDPC compared to the highest grain-yielding commercial cultivar. Based on the farmers' preference criteria for a desirable wheat genotype, the best progeny lines ranked from 3rd to 5th, whereas the two commercial cultivars ranked 1st (Gautam) and 2nd (BL 1473). Results indicated that selection was effective in combining adaptation genes present in a local cultivar with some level of tolerance to spot blotch and resistance genes from exotic genotypes, which translated into improved agronomic performance and disease resistance. The selection index and farmer participatory approach used in this study could serve as a guideline in breeding efforts targeted for high yielding genotypes for wheat-growing conditions in South Asia where spot blotch is a serious biotic constraint to yield.     

在一对面包小麦杂交后代中Glu—B1控制的麦谷蛋白亚基17 18对烘烤品质的影响

将两个优质面包小麦品种安农8455(含Glu-Bl控制的7 8亚基)和Yecora Rojo(含Glu-Bl控制的17 18亚基)进行杂交,测定了其F_3代重组株系的高分子量麦谷蛋白亚基组成、SDS沉降值、伯尔辛克值、蛋白质含量和籽粒产量以及收获指数。利用方差分析、协方差分析和回归分析说明了,17 18亚基对面包品质的作用明显优于7 8亚基,两者的品质差异随着蛋白质含量的增加而增大。文中讨论了17 18亚基在培育较高面包品质潜力的小麦品种中的利用价值。     

Leaf shape × sowing density interaction affects chickpea grain yield

Modifying plant architecture is considered a promising breeding option to enhance crop productivity. Modern chickpea (Cicer arietinum L.) cultivars with either compound (wild‐type) or simple leaf shapes are commercially grown but the relationships between leaf shape and yield are not well understood. In this study, a random sample of ‘Kabuli’ type progeny lines of both leaf types, derived from two crosses between modern American simple leaf cultivars and early‐flowering wild‐type breeding lines, were planted at different sowing densities. Leaf area development and final grain yield in genotypes of the two leaf types responded differently to changes in sowing densities. Compound leaf lines attained higher leaf area indices and higher grain yields at both low and high sowing densities. Yield responses of the simple leaf lines to increasing sowing density were significantly higher compared to compound leaf genotypes in two of three field experiments. The prospects for utilizing the simple leaf trait as a breeding target for short‐season growing areas are discussed.     

Genetic variation in drought tolerance at seedling stage and grain yield in low rainfall environments in wheat (<Emphasis Type="Italic">Triticum aestivum</Emphasis> L.)

Genetic architecture of seedling drought tolerance is complex and needs to be better understood. To address this challenge, we developed a protocol to identify the most promising drought-tolerant genotypes at the seedling stage in winter wheat. A population of 146 recombinant inbred lines (F₉) derived from a cross between wheat cultivars, ‘Harry’ (seedling drought tolerant) and ‘Wesley’ (seedling drought susceptible) were used in this study. All genotypes were sown in three replications in a randomized complete block design under controlled conditions in a greenhouse. Seven traits were scored and grouped into tolerance traits; days to wilting, leaf wilting, and stay green and survival traits; days to regrowth, regrowth, drought survival rate, and recovery after irrigation. Three selection indices were calculated (1) tolerance index, (2) survival index, and (3) drought tolerance index (DTI). The same set of genotypes were also tested for grain yield in two low rainfall environments for two seasons. High genetic variation was found among all genotypes for all seedling traits scored in this study. Correlations between tolerance and survival traits were weak or did not exist. Heritability estimates ranged from 0.53 to 0.88. DTI had significant phenotypic and genotypic correlations with all seedling traits. Genotypes were identified with a high drought tolerance at the seedling stage combined with high grain yield in low rainfall. Breeding for tolerance and survival traits should be taken into account for improving winter wheat drought tolerance at seedling stage. The selected genotypes can be used for to further improve drought tolerance in high yielding wheat for Nebraska.     

Wheat grain yield and stability assessed through regional trials in the Eastern Gangetic Plains of South Asia

Improving the level and stability of grain yield is the primary objective of wheat breeding programs in the Eastern Gangetic Plains (EGP) of South Asia. A regional wheat trial, the Eastern Gangetic Plains Yield Trial (EGPYT), was initiated by CIMMYT in collaboration with national wheat research programs in Bangladesh, Nepal, and India in 1999–2000 to identify wheat genotypes with high and stable grain yield, disease resistance, and superior agronomic traits for the EGP region. A set of 21 wheat experimental genotypes selected from a regional wheat screening nursery in South Asia, three improved widely grown cultivars (Kanchan, PBW343 and Bhrikuti), and one long-term cultivar (Sonalika) were tested at 9–11 sites in six wheat growing seasons (2000–2005) in the EGP. The 21 experimental genotypes were different in each year, whereas the four check cultivars were common. In each year, one or more of the experimental genotypes showed high and stable grain yield and acceptable maturity, plant height, and disease resistance compared to the check cultivars. Three improved cultivars have already been commercially released in the region through EGPYT and many germplasm lines have been used in the breeding programs as parents. Identification of wheat genotypes with high-grain yield in individual sites and high and stable yield across the EGP region underlines their value for regional wheat breeding programs attempting to improve grain yield and agronomic performance.     

Expression of seed storage proteins responsible for maintaining kernel traits and wheat flour quality in common wheat under heat stress conditions

Heat stress during grain filling has been documented to decrease wheat grain yield and quality in arid regions worldwide. We studied the effect of heat stress on wheat flour quality in heat tolerant cultivars to define the effects of heat stress on flour quality and to identify germplasm combining traits for heat tolerance and good flour quality. We studied the kernel phenotypic traits, the expression of seed storage proteins (SSPs), and the resulting flour quality under heat and normal conditions. Under heat stress, all cultivars yielded narrow-shaped seeds, and increased protein contents as compared to the control plants grown under normal conditions. The specific sedimentation values used to estimate the gluten quality varied between cultivars. We identified cultivars that could maintain good flour quality under heat stress conditions: ‘Imam’, which possessed the Glu-D1d allele responsible for the suitable bread-making; ‘Bohaine’, which displayed high expression level of SSPs; and ‘Condor’, which possessed slight variations in the ratio of each SSP under heat stress conditions. Combining the desirable traits from these cultivars could yield a wheat cultivar with heat tolerance and good flour quality.     

Use of the SDS-sedimentation test and SDS-polyacrylamidegel electrophoresis for screening breeder's samples of wheat for bread-making quality

Summary Gelprotein or SDS-insoluble gel-forming glutenin was isolated from wheat flour by extraction with an aqueous 1.5% SDS solution. Remarkable intervarietal differences were observed both in amount and subunit composition of these proteins.The amount of gelprotein and the SDS-sedimentation volume both proved to be good parameters for the bread-making quality of wheat cultivars. A high correlation was observed between amount of gelprotein and SDS-sedimentation volume. The amount of gelprotein was therefore tentatively assumed to be the essential basis of the SDS-sedimentation test.The subunit composition of the gelprotein was studied by SDS-PAGE after reduction of SS bonds by mercaptoethanol. It was found that the average bread-making quality of wheat cultivars and progeny of the cross Atlas 66 x Atys which possessed subunits 3 and 10, coded for by chromosome 1D, was significantly higher than that of wheat samples possessing subunit 2 and 11, their allelic counterparts.     

黄淮旱地冬小麦主要性状演变规律研究

分年代系统地总结了我国黄淮冬麦区2000-2017年旱地冬小麦区域试验233份参试材料共339次试验的产量变化差异,分析比对区域试验对照品种、参试品系产量差异和遗传变异情况,提出了“3年1小旱,5年1大旱”的气候特点是旱地小麦品种选育和产量水平均衡提高的严重障碍,适于较强干旱条件下的抗旱品种、节水节雨品种和优质强筋品种的选育是我国黄淮冬麦区旱地小麦育种当前和今后的主要发展方向。探讨了我国黄淮旱地冬小麦区域试验参试品系和通过国审育成品种产量潜力、变异范围、品质类型等方面的进展和育种研究中存在的问题。     

Combining frost tolerance,high grain yield and good pasta quality in durum wheat

Growing in Central Europe winter instead of spring durum wheat would substantially increase yield potential but is currently hampered by the lack of knowledge of frost tolerance present in elite material. The objectives of our survey were to (i) study the genetic variability and heritability of frost tolerance and its association with other important agronomic and quality traits in durum wheat, (ii) examine the potential to combine frost tolerance with high quality and high grain yield and (iii) investigate the consequences of the heritabilities and associations among traits on the optimum design of a multistage selection programme for winter durum wheat. We investigated 101 elite winter durum wheat lines and four commercial checks in field trials at four locations. Four agronomic as well as nine quality traits were recorded. In addition, frost tolerance was evaluated using a semi‐controlled test resulting in high‐quality phenotypic data. Genotypic variances (σ²_G) were significantly larger than zero for all traits, and heritabilities were moderate to high. Several elite durum wheat lines exhibited a frost tolerance comparable to that of two frost‐tolerant Triticum aestivum varieties. Frost tolerance was not negatively associated with other important agronomic and quality traits. The high quality of the phenotypic data for frost tolerance evaluated in a semi‐controlled test suggests that this is a cost‐efficient approach to consider frost tolerance at early stages of a multistage durum wheat breeding programme.     

Progress since the 1930s in Breeding for Yield, its Components, and Quality Traits of Spring Wheat in Finland

The contribution of improvements in morphophysiological traits to increased gram yield in spring wheat (Triticum aestivum L.) and the achievements of breeding for high bread-making quality in Finland since the 1930s were assessed. Ten wheat cultivars released in Finland between 1939 and 1990 were evaluated in Held experiments at the Viikki Experimental Farm, University of Helsinki, Finland (60°13′N) in 1991 and 1992. Twenty-two traits representing maturity, plant architecture, plant stand structure and N accumulation, and nine quality traits, including protein concentration and protein quality, were assessed. A 20 % increase in grain yield arising from cultivar improvement was associated with a 7 % reduction in height, an 80 % improvement in lodging resistance, and a 15 % higher harvest index (HI). Ear weight was 30 % higher in the modern cultivars. The higher ear weight of the modern cultivars was a result of more grains per ear and a higher spikelet weight. No decrease in vegetative phytomass in modern cultivars was recorded in this study. Grain yield and total N accumulation increased simultaneously and a positive correlation between year of cultivar release and nitrogen index was established. Although use of high N fertilizer application rates resulted in significantly improved baking quality of the flour, no trend between baking quality and year of cultivar release was recorded. The relatively low HI recorded in this study suggests that further yield increases art-likely to be achieved by selecting for higher HI.     

Genetic variation and interrelationships of agronomic characters in landraces of bread wheat from southeastern Iran

There is renewed interest in wheat landraces as important sources of genetic variation for agronomic characters. Fifty-three pure lines of bread wheat (Triticum aestivum L.) derived from seven landraces collected from southeastern Iran were used to estimate genetic variation and heritability for 13 developmental and quantitative characters. Path-analysis was used to partition the genetic correlations between grain yield and six grain yield-related traits. Mean values of landraces were also compared with three improved cultivars from California and Iran. Genotypic differences among the landraces and among the pure lines collected from the landraces were highly significant for all characters considered. Compared with the modern cultivars, the landrace genotypes were, on average, later in days to heading and taller than the cultivars but had lower values for number of grains per spike, 1000-grain weight, grain yield and harvest index. Some landrace genotypes were similar to the modern cultivars for grain yield. Moderate to high genetic variation was displayed by number of grains per spike, number of spikes per plant, 1000-grain weight, and harvest index. The heritability estimates ranged from 59% for grain yield to 99% for days to anthesis. Expected genetic advance (as % of the mean) was ≈34% for number of spikes per plant, number of grains per spike, and 1000-grain weight. Days to heading and to anthesis correlated positively with number of spikes per plant, shoot biomass, and straw biomass but negatively with number of grains per spike and harvest index. The strong direct effect of number of spikes per plant on grain yield was completely counterbalanced by its indirect negative effects via number of grains per spike and 1000-grain weight. Number of grains per spike and 1000-grain weight were positively correlated with grain yield, and they had large direct effects. These two characters, however, were negatively correlated and exhibited a substantial counterbalance effect via one another and via number of spikes per plant. The landraces could be improved by intercrossing the promising genotypes identified in this study, with simultaneous selection for earliness, fewer number of spikes per plant, greater number of grains per spike and heavier grains. For further improvement, crossing programs between the landraces and introduced germplasm may be necessary. This revised version was published online in July 2006 with corrections to the Cover Date.     

我国玉米自交系叶片保绿性及其与产量的关系

选用我国75个常用不同基因型玉米自交系,对其叶片保绿性参数进行了定点动态测定。结果表明,不同自交系抽丝后叶片保绿度的变化均符合方程y = ae^b-cx/ (1+e^b-cx),成熟期的绿叶数、成熟期叶绿素含量和相对绿叶面积平均衰减速率(V_m)可作为区分玉米保绿型与非保绿型的关键指标。按照Hiechical聚类分析方法,筛选出12个保绿型自交系,其成熟期相对绿叶面积在60%以上,其V_m平均值为0.687% d^-1,在生长季内相对绿叶面积无大幅度衰减,成熟期绿叶数多,叶绿素含量较高;其余63个为非保绿型自交系,还可分为植株叶片衰老较快型与植株叶片衰老较慢型两个亚类。不同自交系抽丝后叶片保绿性与叶面积持续期、单株产量均呈正相关。保绿型的叶面积持续期和单株产量比非保绿型分别高20.02%~23.87%和50.44%~59.38%;与非保绿型自交系相比,保绿型在籽粒灌浆期绿叶面积大,叶绿素含量高,群体光合速率高,光合作用时间长,因而生物产量较高。     

Comparative evaluation of exotic and adapted germplasm of spring wheat for floral characteristics in the Indo-Gangetic Plains of northern India

Four hundred spring wheat genotypes, comprising exotic and indigenous germplasm and adapted cultivars for commercial cultivation, were investigated during four crop seasons for six floral characteristics related to outcrossing behaviour. Genetic variability and heritability were investigated along with phenotypic correlation coefficients among these characteristics. A significant quantitative variation existed among the characteristics in all three groups. High heritability for stigma length, openness of florets, anther extrusion and duration of floral opening indicated that selection for these characteristics may be effective. The adapted cultivars were found more promising than the exotic and indigenous germplasm. Most of the characteristics showed significantly positive correlation with each other and high correlation was observed between anther and stigma length, and anther extrusion and duration of floral opening. Superiority of varietal mixtures and segregating generations (F₃ and F₄) of two crosses over parental lines suggested that heterozygosity and heterogeneity can provide yield advantages. Germplasm lines possessing superior expression of floral characteristics may be used to improve yielding ability through enhanced heterozygosity or the development of hybrids.