Seed yield and its components in smooth bromegrass (Bromus inermis Leyss.) cultivars

Summary Seed yield performance and effect on seed yield of morphological traits such as seeds/panicle, seed weight, seeds/branch, branches/2nd node, branches/panicle, fertile tillers/plant and panicle length were evaluated in 13 cultivars of smooth bromegrass in a spaced-plant nursery. Wide variation was observed between and within cultivars for seed yield and traits. Highly significant correlation coefficients were found among traits and seed yield. Path analysis showed that specifically seeds/panicle and seed weight had strong direct effect on seed yield. It was concluded that seeds/panicle and seed weight were primary selection criteria for seed yield in smooth bromegrass.     

Components of Seed and Straw Yield in Common Vetch (Vicia sativa L.)

178 common vetch (Vicia sativa L.) strains were tested for 2 years under dryland conditions in Bursa, Turkey. Broad-sense heritability of the traits was calculated for each trait. Phenotypic and genotypic correlation coefficients between seed and straw yield, with several morphological and reproductive traits, were obtained. Broad-sense heritability estimates were high for 1000-seed weight and number of seeds per pod. Heritability values for both seed and straw yield were small and insignificant. Harvest index, 1000-seed weight and spring vigour showed significant positive correlations with seed yield, but days to flower correlated negatively with seed yield. Spring vigour, plant height and number of leaflets per leaf correlated positively, while harvest index, seeds per pod and seeds per plant correlated negatively with straw yield. Correlations between seed and straw yield were both positive and significant.     

玉米自交系植株性状状与单株产量相关性研究

为研究玉米自交系主要植株性状与单株产量的相关性,选择代表性的父本、母本自交系采取随机区组设计,测定其主要植株性状和单株产量。结果表明,穗行数、行粒数、穗位高、雄穗分支数、节间长与单株产量均显著正相关,其中,穗行数与单株产量的相关性最强,相关系数达0.8824。株高与节间长、穗位高（r=0.7372）、穗行数和雄穗分支数显著正相关。穗长与百粒重极显著正相关(r=0.6631)。出籽率与穗行数、行粒数极显著正相关。在自交系选育过程中,穗行数、行粒数等穗部性状直接影响自交系的单株产量,但株高等同样是自交系选育的关键性状,自交系选育要兼顾穗部性状和植株性状,以获得株型适中兼大穗型的高产品种。     

盐逆境对耐盐水稻穗部性状及产量构成因素的影响

探明不同盐逆境水平对耐盐水稻穗部性状及产量构成因素的影响,旨在为沿海滩涂水稻种植和耐盐水稻高产育种提供科学依据.以'扬农稻1号'(V1)、'南粳5055'(V2)和'通海粳18-2'(V3)为试材,利用盐池设施设置O g/kg(S0)、1.5 g/kg(S1)、3 g/kg(S2)3个不同盐分水平,采用裂区试验,测定分...     

Phenotypic and genotypic variation in seed production traits within a full-sib family of meadow fescue

Phenotypic and genotypic variation for seed yield and associated traits (heading date, plant height, number of fertile tillers, 1000‐seed weight, panicle length, seed weight per panicle, fertility, flag‐leaf length and flag‐leaf width) were studied in a full‐sib family of meadow fescue using replicated clonal trials at two locations in Norway. Genotypic variances were highly significant for all traits and genotype × location interactions were significant for heading date, number of fertile tillers and seed yield. Seed yield and other seed component traits exhibited the largest genotypic variations. Heading date showed large genotype × location interaction, probably because of the very diverse origin of the two parents of the full‐sib family. Path coefficient analysis showed that panicle fertility, measured as seed weight per unit length of panicles, was by far the most important component trait contributing to seed yield, followed by the number of fertile tillers, plant height and flag‐leaf width. Flag‐leaf width and plant height had sizeable indirect effects on seed yield via panicle fertility. This is the first time that the importance of the size of the flag leaf for seed yield in herbage grasses has been demonstrated.     

Genetic variability and interrelationships of seed yield and yield components in switchgrass

Information on the genetic variability of seed yield and yield components is limited and no information is available on correlations among seed yield and yield components and direct and indirect effects of the yield components on seed yield in switchgrass, Panicum virgatum L. Accordingly, we conducted replicated experiments at Chickasha and Perkins, OK, in 1998 involving 11 lowland type switchgrass populations to assess genetic variation for seed yield and yield components, quantify interrelationships among them, and determine direct and indirect effects of yield components on seed yield through path coefficient analysis to identify traits for indirect selection of seed yield. Significant (P ≤ 0.01) variation existed among the 11 populations over locations for percent seed set and 100-seed weight. Seed yield/plant and the seed yield components panicle number/plant, spikelet number/panicle, and seed number/panicle had significant (P ≤ 0.05) population × location interactions, indicating substantial environmental influence on these traits for these populations. Accordingly, data for these traits were analyzed separately for each location revealing significant (P ≤ 0.01) differences among populations at both locations for each of these traits. Phenotypic correlation between seed yield/plant and seed number/panicle was positive (r = 0.76** at Chickasha and r = 0.72** at Perkins). Path coefficient analyses revealed that seed number/panicle had the highest positive direct effect on seed yield at both locations. Ample genetic variability was present among the switchgrass populations studied to allow breeding improvement of seed yield. Selection for increased seed number/panicle would be the most effective means of indirectly selecting for higher seed yield within this germplasm. Correlation and path coefficient analyses among biomass yield, seed yield, and harvest index indicated that, at least within the switchgrass germplasm studied, it would be possible to breed switchgrass cultivars with enhanced biomass yielding ability and sufficient seed production capability for their commercial propagation.     

水稻籼爪交和粳爪交杂种优势的研究Ⅱ.农艺性状的杂种优势分析

研究了籼爪交和粳爪交杂种在长沙、三亚的农艺性状和干物质产量的杂种优势.在长沙的籼爪交杂种在结实率和每穗实粒数方面具有负向超亲优势,在每穗实粒数、结实率、单株粒重和理论产量方面存在负向对照优势,其余性状均为正向优势;粳爪交杂种在千粒重和结实率方面存在负向超亲优势,其余性状为正向超亲优势, 在始穗期、秆高和单     

钵苗机插密度对不同穗型水稻品种产量、株型和抗倒伏能力的影响

选用3种穗型水稻品种,设置3种钵苗机插密度,以毯苗机插为对照(CK),系统研究钵苗机插不同密度对水稻产量及其构成、穗部性状、冠层叶系配置、茎秆物理特性和抗倒伏的影响,旨在探明水稻钵苗机插配套不同穗型品种适宜栽插规格及其增产特点;同时,阐明钵苗机插不同密度下水稻株型特征和抗倒伏特性。结果表明:(1)3种钵苗机插密度处理下,大穗型品种产量随密度降低呈先增后降的变化趋势,但均显著高于CK;中、小穗型品种产量有随着密度降低而下降的趋势。不同穗型品种穗数随着密度降低而显著减少,每穗粒数显著增加,结实率和千粒重无明显变化规律。(2)钵苗机插下不同穗型水稻品种的穗长、着粒密度、单穗重、一次枝梗数、二次枝梗数、一次枝梗粒数和二次枝梗粒数均随密度降低而增加,且高于CK;一、二次枝梗数比值和一、二次枝梗粒数比值随密度降低而呈下降趋势。(3)钵苗机插下不同穗型水稻品种的上三叶的叶长、叶宽、叶基角、披垂度和比叶重随着密度降低而呈增加趋势;且上三叶的叶长、叶宽和比叶重高于CK。(4)随着密度降低,不同穗型品种钵苗机插水稻基部N1、N2、N3节间长度减少,茎秆粗度、茎壁厚度和节间干重增加,穗下节间长、秆长、株高、重心高增加,而相对重心高有减小趋势。(5)不同穗型品种钵苗机插水稻基部节间N1、N2、N3抗折力和弯曲力矩随着密度降低而增加,倒伏指数呈下降趋势,且低于CK。说明水稻钵苗机插配套大穗型品种宜适当降低密度,增加每穗粒数以获高产;中穗型品种需兼顾穗数和每穗粒数,提高群体颖花量而增产;小穗型品种依靠穗数而提高产量。水稻钵苗机插降低密度能改善穗部性状和增加上三叶的叶面积,但增大了叶基角和披垂度,同时利于缩短基部节间长度,增加基部节间粗度、茎壁厚度和充实度,从而提高抗折力,降低倒伏指数。     

Bilateral polyploidization inDactylis glomerata L. subsp.lusitanica: occurrence,morphological and genetic characteristics of first polyploids

Summary InDactylis glomerata L. subsp.lusitanica, triploid and tetraploid plants were obtained by bilateral sexual polyploidization in crosses between diploid parents known to produce 2n gametes. The polyploid and diploid progeny were compared for allozyme diversity (allele number and heterozygosity), phenological (pollen fertility, inflorescence emergence date), cellular (stomatic cell size) and morphological characters (vegetative biomass, seed weight, total seed number per plant, panicle number and seed number per panicle length) in four contrasting growing conditions. Stomatal cell size and the total number of alleles were significantly lower in diploids than in polyploids which sometimes recovered more than two distinct alleles at a locus via 2n gametes possessing heterozygous loci. Pollen fertility was similar in diploids and tetraploids, but significantly lower in the triploids. Seed weight was significantly higher in polyploids, although the average number of seeds per panicle length and the total number of seeds was higher in the diploid sibs. No phenological differences occurred among ploidy levels whereas such differences were observed inDactylis in all the natural areas of sympatry between diploids and their related polyploids. Our results provide evidence for an instantaneous effect of polyploidization on certain traits and suggest that natural selection would act subsequently on several other traits to allow the establishment of new polyploids.     

水稻种子包衣剂应用效果研究

用15%多福悬浮种衣剂对水稻种子进行包衣处理,研究发现:在秧苗期,该种衣剂能提高秧苗茎蘖数、根长、鲜重和叶绿素含量,对苗高、叶龄和根数的影响不明显.对水稻经济性状及产量调查发现,种衣剂能显著提高每窝穗数、有效穗、穗平均着粒数、理论产量和实际产量,对株高、穗长、穗平均实粒数、结实率和千粒重等效果不明显.     

The utility of hill plots in oat research

From 1955 through 1963, approximately 300,000 hill plots have been used in various experiments in the Iowa small grain research program. When grain yield, plant height, and heading date were measured on the same varieties, the genetic correlations between rod rows and hills were 0.98, 0.96 and 0.96, respectively.The coefficients of variation for plant height, weight per volume, spikelets per panicle, panicles per plant, weight per 100 seeds were similar for rod rows and hills. However, the coefficients of variability for grain yield ranged from 2 to 5 times larger for hills than for rod rows. Competition between varieties in adjacent hills had little effect on the performance of varieties.The best method for planting hill plots is the conventional method opening a hole in the soil about 2 inches deep with a hoe, pouring the seed in the hole, and covering it with soil. Rates of planting influenced the expression of grain yield, panicles per plant, and spikelets per panicle, but not weight per 100 seeds and plant height. Approximately 30 seeds per hill appeared the most desirable planting rate.Journal Paper No. J-5064 of the Iowa Agricultural and Home Economics Experiment Station, Ames, Iowa. Project No. 1176. Received for publication Febr. 23, 1965. In cooperation with the Crops Research Division, Agricultural Research Service, U. S. Department of Agriculture.Professor of farm crops.     

不同光周期环境对谷子农艺性状的影响

本研究连续2年在短日照(海南)、中等日照(河南)、长日照(吉林)3个不同光周期环境调查160份谷子资源的抽穗期、株高、叶片数、穗长、穗粗、穗码数、码粒数、穗重、穗粒重、千粒重10个主要性状,利用SPSS19.0软件进行多因素方差分析及多重比较,揭示光周期对谷子各性状的影响,评价160份谷子资源对光周期的敏感性。结果表明,3个不同光周期环境间谷子株高、叶片数、穗长、穗码数、抽穗期、穗粗、穗重、穗粒重、码粒数9个性状均表现出极显著差异(P0.01),千粒重表现出显著差异(P0.05)。株高、叶片数、穗长、穗码数、抽穗期5个性状随着日照的延长呈现出递增趋势。品种对谷子的10个性状有极显著影响(P0.01),年份对千粒重以外的9个性状有极显著影响(P0.01)。光周期与品种互作效应对10个性状均有极显著影响(P0.01),光周期与年份互作效应对抽穗期以外的9个性状有极显著影响(P0.01),年份与品种互作效应对株高、叶片数、穗长、穗粗、穗重、穗粒重、穗码数、码粒数8个性状有极显著影响(P0.01)。160份谷子资源中对光周期表现中、低敏感性的材料没有明显的地域特性,而对光周期表现强敏感性的材料主要是来自春谷区的农家品种。筛选出光周期极不敏感材料小早谷和极端敏感材料呼和浩特大毛谷、然谷、红钙谷、茄谷、二白谷等,为选育谷子光周期钝感品种及开展光周期敏感性形成机理研究奠定了基础。     

Sunflower seed yield as influenced by some agronomic and seed characters

Summary An investigation was made to the interrelationships of agronomic and seed characters and their effect upon seed yield. Twenty genotypes of sunflower (Helianthus annuus L.) from diverse origin were studied in spring and autumn season, 1989.Most of the studied characters exhibited different relationships in spring and autumn seasons. The correlations between plant height and oil content, 100-achene weight and number of achenes per head and plant height and head diameter were, however, consistent in both seasons and across the seasons. Stepwise multiple regression analysis identified six relevant characters on which path analysis was done.Path analysis indicated that yield components like head diameter, number of achenes per head and 100-achene weight had comparatively smaller direct effects on seed yield (0.22, 0.15 and 0.23, respectively). Days to physiological maturity, plant height and oil content had relatively stronger direct effects on seed yield (0.33, 0.38 and 0.29, respectively). Days to physiological maturity, plant height and head diameter had considerable indirect effects. Head diameter, 100-achene weight and number of achenes per head were indentified as selection criteria for yield improvement.     

水条播对寒地水稻农艺性状和产量构成因素的影响

随着劳动力的短缺,直播水稻具有省工省力的优点逐渐受到重视,因此筛选适宜水条播（直播）的水稻品种是极其重要的。为此,以29份寒地水稻为材料,采用随机区组试验设计,研究水条播对寒地水稻农艺性状、产量构成因素和产量的影响。结果表明,水条播对寒地水稻单位面积穗数的影响为偏正向,对株高、穗长、穗重、一次枝梗数、二次枝梗数、穗粒数、成粒率、千粒重、生物产量、经济系数和理论产量的影响都是偏负向的。水条播提高了穗重、一次枝梗数、二次枝梗数、单位面积穗数、穗粒数、成粒率、千粒重、生物产量、经济系数和理论产量的变异程度,而千粒重的变异系数较小。穗重、成粒率和生物产量对水条播反应较敏感的材料,一般其理论产量对水条播的反应也较敏感。     

籼糯稻产量性状及育种分析

为了提高常规籼糯稻育种和栽培水平及效率,通过相关和通径分析,研究40个早籼糯以及61个晚籼糯新品系和品种的产量性状对产量的效应及其相互关系,并结合育种实践探讨籼糯稻高产育种的主攻方向。结果表明：早籼糯各产量性状除生育期、结实率外均与产量呈极显著或显著正相关,株高、穗长与每穗粒数之间的相关分别达极显著、显著水平,有效穗数对产量贡献最大(46.41%),其次为每穗粒数(34.16%);晚籼糯的每穗粒数、有效穗数与产量的正相关分别达极显著、显著水平,株高与每穗粒数、穗长之间的相关也达显著水平,每穗粒数对产量贡献最大(38.80%),其次为有效穗数(33.80%)。并根据试验结果和育种实践,提出早籼糯稻的育种主攻方向是在一定千粒重基础上重点提高有效穗数,并通过适当提高株高、穗长来增加每穗粒数;晚籼糯稻育种主攻方向是在一定有效穗数的基础上着重提高每穗粒数,并通过增加植株高度来提高穗长和每穗粒数。     

大豆单株产量与主要农艺性状的灰色关联度分析

为了探讨大豆各主要农艺性状对单株产量影响的主次关系,以黑龙江省第二积温带种植的6个大豆品种为试验材料,应用灰色系统理论的关联度分析法对与大豆单株产量相关的8个性状进行关联分析。结果表明：大豆单株产量相关性状的灰色关联度大小依次为单株粒数>主茎分枝数>单株有效荚数>百粒重>底荚高度>株高>生育期>主茎节数,与单株产量最为密切相关的性状是单株粒数,其与产量的关联度为0.42,其次是主茎分枝数,与产量的关联度为0.39,主茎节数影响相对较小。因而,在大豆品种选育过程中,应注重单株粒数多和主茎分枝数多的品系选育。     

Genetic analyses of agronomic and seed quality traits of doubled haploid population in Brassica napus through microspore culture

Summary The results showed that the F1 genotype from the cross (Brassica napus cv. Zheshuang 758 × cv. Z-4115) had good response to embryogenesis, and their embryo yield and rate of plant regeneration reached 69.8 embryo/bud and 46.9%, respectively. Characters from the doubled haploid (DH) populations in B. napus were analyzed and it was showed that the means of each agronomic trait were between their parents, but they were nearer to the paternal in 6 agronomic traits (plant height, branch position, number of pods in the main raceme, length of pod, number of pods/plant and number of seeds/pod). The number of genes controlling each agronomic trait was analyzed based on the DH populations. The results showed that the number of genes controlling number of pods in the main raceme was the highest (15.6), and the least number of genes was involved for stem width (only 7.9). According to estimated coefficients of skewness and kurtosis of the traits tested, gene interaction was found to be absent for stem width, plant height, length of main raceme, number of primary and secondary branches, pod density in the main raceme and seed weight/plant. Complementary interaction was also observed in five agronomic traits (number of pods in the main raceme, length of pod, number of pods/plant, number of seeds/pod and 1000-seed weight). A significantly positive correlation was observed between seed yield/plant and four agronomic traits (length of main raceme, length of pod, number of pods/plant and 1000-seed weight). The experiment also showed that the erucic acid, glucosinolate, oil and protein contents of DH populations were 34.23%, 87.09 μmol/g, 44.09% and 42.67%, respectively. The numbers of genes controlling each quality trait were 7.8, 9.7, 9.4 and 8.7, respectively. Partial correlations between the seed quality traits and the agronomic characters of DH populations were analyzed. In this experiment, the partial correlations among seed quality traits were also analyzed and it was found that the oil content had a negative correlation with the other three seed quality traits.     

Bud pollination and hybrid seed production in detergent-induced male sterile plants of Brassica juncea

The efficacy of a synthetic detergent (Surf Excel) as a potential chemical hybridizing agent in Brassica juncea was studied. Foliar sprays with various concentrations of the detergent caused reductions in plant height, number of branches and leaves per plant, size of leaves, anther size, pollen per flower, ovules per flower, pollen fertility, fruits per plant, fruit size, seeds per fruit, total yield per plant and 100 seed weight as compared with those of untreated plants. The style in the floral buds of plants sprayed with different concentrations of Surf Excel elongated and so the receptive stigma protruded from the buds which facilitated cross‐pollination by honey bees. The plants sprayed once with 2% Surf Excel exhibited an elongated style with a raised receptive stigma and 100% pollen sterility without causing a significant reduction in total yield.     

甘蓝型油菜DH群体若干数量性状的遗传分析

为了研究甘蓝型油菜DH群体包括株高、分枝高度、一次有效分枝数、主花序长度,主花序角果数,生物产量,经济产量以及千粒重等数量性状间的遗传关系。通过对DH群体及亲本若干数量性状数据的表型分析、偏相关分析、遗传力和最少基因对数估计以及基因间互作方式分析。结果表明：分枝高度、主花序长度、主花序角果数和单株生物产量偏向于父本,而一次有效分枝数偏向于母本。株高、经济产量和千粒重则表现为超亲遗传。多数性状之间存在极显著正相关,但是分枝高度与一次有效分枝数,主花序长度与一次有效分枝数,主花序角果数与一次有效分枝数间均呈极显著负相关。分枝高度遗传力最高为83.31%,千粒重遗传力最低为60.9%。控制各性状的最少基因对数分别为13.8、12、23、12.5、24.7、20.9、11.1和13.8对。对各性状遗传力以及偏度系数和峰度系数的估算表明,控制株高和分枝高度的基因间没有互作;控制一次有效分枝数基因间存在互补作用,控制主花序角果数、生物产量和千粒重基因间可能存在互补作用;控制主花序长度和经济产量的基因间可能存在重叠作用。