辽宁水稻穗型分类及其与产量和品质的关系

以辽宁省近年来育成的40个水稻品种为试材,研究了穗部性状的品种间差异、穗型分类方法及其与穗部性状、产量和品质的关系。结果表明,调查的13项穗部性状的品种间差异均达到极显著水平;以单穗重、着粒密度、穗直立程度和穗型指数为指标,分别将试材划分为重、中、轻,密、中、稀,直、半、弯,上、中、下4类各3种穗型;总体看重穗型有与密穗型相对应的趋势,共同特点是穗数少而一次枝梗数和每穗粒数多,着粒密度大,二次枝梗粒数及其占每穗粒数的比率（二次粒率）高,结实性特别是二次枝梗结实性差,因而产量潜力较高但是品质较差;直立穗型与重穗型和密穗型的对应关系不如前两者之间明显,在穗数、一次枝梗数、每穗粒数、着粒密度等方面与重穗型和密穗型相似,但是二次粒率低,结实率高,加工品质、外观品质和食味品质都优于重穗型和密穗型;上部优势型在结实性和品质性状上有明显优势,但是产量较低。因此,直立穗型与上部优势型相结合将有利于北方粳稻产量和品质的协调统一。     

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.     

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...     

豌豆主要农艺和品质性状的相关性及灰色关联度分析

采用灰色关联分析和相关分析相结合的方法,对8份豌豆品种（系）的主要农艺和品质性状进行了综合描述和客观评价。结果表明,单株产量与单荚粒数、百粒重呈正相关;产量与主要农艺性状的关联度表现为单荚粒数>单株荚数>生育日数>百粒重>株高>单株分蘖数>主茎节数>单株产量;豌豆品质性状与品质优劣的关联度表现为粗蛋白含量>粗淀粉含量>赖氨酸含量>水分含量>粗脂肪含量,这与相关分析结果一致,可以将两种方法结合起来进行品种的客观评价。     

Seed yield related to crop development and to yield components in nine cultivars of perennial ryegrass (Lolium perenne L.)

Summary We had previously found differences for seed yield among nine perennial ryegrass cultivars which were not associated with variation for seed weight. To detect the physiological basis of these genetic differences for seed yield, growth analyses were carried out. We related crop development and components of seed yield to seed yield during three years on clay and sandy soil. No significant differences occurred among cultivars for accumulation and partitioning of dry matter or the pattern of tiller production. Seed yield of the cultivars was not associated with ear number or total dry matter yield of the seed crop. Seed yield was more correlated with the number of seeds per unit area than with seed weight. The number of seeds as calculated after harvest from seed yield and seed weight was much lower than the number of seeds as estimated prior to harvest from seed yield components. The number of spikelets differed significantly among the cultivars, but the ranking was different from that for seed yield. The physiological basis of the genetic differences for seed yield is not clear. Implications for breeding perennial ryegrass are discussed.     

两种穗型粳稻穗上不同粒位籽粒几个营养和蒸煮品质性状的比较分析

选用典型的直立穗型和弯曲穗型粳稻品种, 研究了穗上不同粒位籽粒的几个重要营养和蒸煮品质性状差异及其分布特点。结果表明, 穗型特征与蛋白质含量、直链淀粉含量和食味值高低无直接必然的联系, 但是对穗不同部位间这些指标及其粒位顺序有较大影响。对3个直立穗型品种而言, 蛋白质含量、直链淀粉含量表现为穗下部＞中部＞上部, 食味值则相反, 而对3个弯曲穗型品种而言, 蛋白质含量、直链淀粉含量的表现规律不明显, 食味值表现为穗上部＞中部＞下部; 同一稻穗不同枝梗间相比, 着生在二次枝梗上的稻米蛋白质含量相对较高、直链淀粉含量和食味值相对较低, 而着生在一次枝梗上的稻米蛋白质含量相对较低、直链淀粉含量和食味值相对较高; 同一枝梗间的不同着粒部位相比, 下部二次枝梗第2、3粒位的蛋白质含量较高、食味值较低, 中上部一次枝梗1~6粒位的蛋白质含量较低、食味值较高, 而直链淀粉含量在粒位间规律不明显; 直立穗型品种单一稻穗不同粒位间的差异大于弯曲穗型品种, 其主要原因可能是直立穗型品种着粒密度过大。     

Traits associated with dry edible bean (Phaseolus vulgaris L.) productivity under diverse soil moisture environments

Two experiments were conducted in the Rift Valley, Ethiopia (8°N and 39°E) to determine associations between eight plant traits and seed yield, and to obtain estimates of narrow sense heritability for the traits. Experiment I evaluated seven dry edible bean cultivars/lines at two locations to simulate different soil moisture stress, including, Debre Zeit(non-stress) and Dera (moderate-stress). Experiment II evaluated 25 cultivars/lines in three environments including, Melkassa early planted (non-stress), Melkassa late planted (high-stress), and Dera (moderate-stress). A randomized-complete-block design with three replicates was used in both experiments. Plant traits evaluated were seed yield, pods plant^-1, seeds pod^-1, 100 seed weight, root dry weight, hypocotyl diameter, plant biomass, plant height and days to flowering. Plant traits that were significantly associated with seed yield were included in a stepwise-regression model to determine which trait or combination of traits provided the best model to estimate seed yield in each environment. An analysis of variance was conducted to test main effects and interactions between plant traits and environments. Significant variation among lines occurred for seed yield and all plant traits in both experiments. Strong positive correlations were observed between plant biomass and seed yield in all environments. Seed yield and pods plant^-1 were also highly associated in four of the five environments. Stepwise regression models indicated that the combination of pods plant^-1 and plant biomass consistently contributed to seed yield prediction, while other traits did not. Because both plant biomass and pods plant^-1 had moderate to high narrow sense heritability estimates and low GE interactions, they should be useful as indirect selection criteria to improve and stabilize seed yield in a breeding program. This revised version was published online in July 2006 with corrections to the Cover Date.     

减氮对辽粳5号/秋田小町RIL群体茎秆维管束、穗部和产量性状的影响及其相互关系

以辽宁稻区典型的直立穗型品种辽粳5号与日本典型的优质米品种秋田小町杂交构建的重组自交系群体(recombination inbred lines, RIL)为试材,在高氮和低氮2种施肥模式下种植,调查RIL群体茎秆维管束、穗部和产量性状,分析减氮对三者的影响及其相互关系,探讨在减少氮肥施用量的同时维持产量稳定的可能途径。研究结果表明,不同施氮模式下,RIL群体的茎秆维管束性状、穗部及产量性状均呈现连续变异,符合多基因控制的数量性状遗传特点。氮肥减施后, RIL群体水稻的单茎穗颈和倒二节间维管束数目、单株穗颈和倒二节间维管束面积减少,一次枝梗数减少,一次和二次枝梗结实率、总体结实率和千粒重增加,单穗重增加,穗数减少,产量降低。茎秆维管束性状与穗部和产量性状关系密切,单茎维管束性状与穗颈粗、一次枝梗数、二次枝梗数、穗粒数、着粒密度、千粒重和单穗重大多呈显著至极显著的正相关,单株维管束面积与穗数和产量呈极显著正相关。氮肥减施后,RIL群体中不减产类型株系的主要特征是:低氮条件下仍能维持稳定的分蘖和茎秆维管束的分化,保证穗数和穗颈粗稳定,单茎穗颈和倒二节大、小维管束数目、单茎倒二节大维管束面积和单株倒二节大维管束面积无显著变化,一次枝梗数变化不显著。在减施氮肥的条件下,选用茎秆维管束发达,穗数和穗颈粗稳定的水稻品种,有可能实现减氮不减产的目标。     

Causes of Sterility in Seed Set of Rice under Salinity Stress

The effects of salinity at 50 mM NaCl on floral characteristics, yield components, and biochemical and physiological attributes of the sensitive rice variety IR‐28 were studied under controlled conditions to determine the causes of sterility in seed set under salinity stress. The results showed significant decreases in panicle weight, panicle length, primary branches/panicle, filled seeds/panicle, unfilled seeds/panicle, filled seeds/plant, unfilled seeds/plant, total seeds/panicle, total seed weight/panicle, 1000‐seed weight and total seed weight/plant. The sodium content in different leaves and floral parts increased significantly. In contrast, the potassium content was decreased significantly in leaves and floral parts. A reduction in chlorophyll a and b was also noted in different parts of the leaves. Inhibition of transpiration and photosynthesis was observed in flag leaves at the grain‐filling stage. Soluble carbohydrates in different leaves were reduced significantly in salinized plants but their content in different floral parts was increased, with the exception of primary and secondary branch spikelets. Under salinity stress, total protein concentration in flag, second and third leaves were higher than in control plants. The viability of rice pollen was reduced significantly in salinized plants. It was further observed that starch synthetase activity (α1–4‐glucan glucosyle transferases) in developing rice grains was inhibited very significantly under salinity stress. From these results, it is inferred that sterility and significant reductions in seed set in rice were not merely due to reduction or inhibition of different biochemical constituents and physiological functions, but were mainly due to limitation of soluble carbohydrate translocation in primary and secondary spikelets, accumulation of more sodium and less potassium in all the floral parts, and highly significant inhibition of specific activity of starch synthetase in developing rice grains, thus resulting in failure of seed set.     

黄淮海夏大豆产量与主要农艺性状的灰色关联度分析

为探讨大豆主要农艺性状对大豆产量影响的主次关系,运用灰色关联度分析法,对黄淮海地区16 个品种12 点试验进行产量与农艺性状的分析,从而为黄淮海地区大豆育种提供理论依据。结果表明：产量与主要农艺性状的关联度大小依次是单株粒重＞分枝数＞株高＞生育日数＞单株荚数＞单株粒数＞主茎节数＞底荚高度＞百粒重。可见,对大豆新品种选育时,应优先考虑单株粒重,分枝数,株高和生育日数。     

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.     

三江平原不同年代大豆主栽品种主要农艺性状及产量变化分析

为了研究三江平原60 余年大豆生产主栽品种更替过程中主要农艺性状与产量的改进与变化规律,指导当前或今后的品种改良与创新,采用田间小区试验的方法,选用三江平原不同年代同熟期组的18 个主栽品种为试验材料。试验结果表明,主要农艺性状随年代的推进,株高与有效分枝数呈降低趋势;底荚高度变化不大,总体呈增加趋势;主茎节数呈增加趋势;抗倒伏能力逐渐增强;生育日数逐年延长;品种单株荚数、每荚粒数、单株粒数、单株粒重均呈不断增加的趋势;百粒重呈波动增加趋势。产量随着年代的推进逐年累加提高,产量变化幅度为2509.20~3311.25 kg/hm2,年平均产量增加13.35 kg/hm2,增长速度为0.53%。由于品种主要农艺性状的改进与变化,特别是品种生育日数延长和产量性状的改进,不断的提高品种产量水平,所以导致了生产主栽品种不断更替与变化,这一结论对当前或今后品种改良与创新具有重要的指导与借鉴意义。     

Phenotypic recurrent selection in common bean (Phaseolus vulgaris L.) based on performance of S2 progenies

Summary The effect of a recurrent selection procedure for improving seed yield per plant was evaluated in common bean. Progress was registered after three cycles of recurrent selection with S2 progeny evaluation performed on the grain yield/plant. Gain from selection was estimated by field testing 45 random S2 lines from each of the C0, C1 and C2 populations. Response to selection for seed yield/plant was 6 g from C0 to C1 and 4.4 g from C1 to C2. The seed yield improvement was due principally to an increase in pods/plant; little contribution was provided by the 1000-seed weight and seeds/pod traits. Broad-sense heritability and genotypic variance for grain yield remained high in all cycles which suggests further gain from additional selection cycles. Grain yield/plant is significantly correlated to pods/plant and seeds/pod traits in all cycles, indicating that plants with favourable combinations of these traits could be identified. The proposed recurrent selection procedure appears to be effective in improving the population and extracting superior genotypes for varietal development.     

Path analysis of the relationships between seed yield and some morphological and phenological traits in safflower (Carthamus tinctorius L.)

Path analysis was performed on plant characters of six safflower genotypes grown in a two year field experiment to determine for seed yield, the direct and indirect effects of the following traits: total biomass, stem yield, number of primary branches/plant, number of secondary branches/plant, number of seeds/m², number of seeds/capitulum, number of capitula/plant, capitulum diameter, 1000-seed weight, seed weight/capitulum, distance between ground level and the first fertile branch, plant height, number of days to the beginning of branching, number of days to the beginning of flowering, number of days to 50% flowering, number of days to full flowering and flowering duration. Seed yield was significantly correlated with the following traits: total biomass, stem yield, capitulum diameter, 1000-seed weight, seed weight/capitulum, distance between ground level and the first fertile branch, number of days to the beginning of branching and flowering duration. Total biomass, seed weight/capitulum, distance between ground level and the first fertile branch, 1000-seed weight and flowering duration had substantial direct effects, in that order, on enhancement of seed yield. The significant positive correlation coefficient of capitulum diameter with seed yield resulted from positive indirect effects of total biomass, seed weight/capitulum and 1000-seed weight. Conversely, the significant negative correlations between number of days to the beginning of branching and distance between ground level and the first fertile branch and seed yield resulted from negative indirect effects of the same three traits. Stepwise multiple regression analysis showed that 94% of the total variation in seed yield could be explained by variation in total biomass and by number of days to the beginning of branching (84 and 10%, respectively). Results suggest that total biomass and number of days to the beginning of branching are primary selection criteria for improving seed yield in safflower.     

Genetic improvement in grain yield potential and associated agronomic traits of tef (<Emphasis Type="Italic">Eragrostis tef</Emphasis>)

A yield potential experiment was conducted with one farmers variety and 10 improved varieties released over the periods 1960–1995 to estimate the progress made in improving grain yield potential and to determine changes produced on agronomic traits associated with genetic yield potential improvement. The experiment was conducted at the Debre Zeit Agricultural Research Center, Debre Zeit, Ethiopia, on two soil types in the 1997 main cropping season, using a randomized complete block design with three replications. Evaluation of cultivars from different eras in a common environment has been used to estimate breeding progress. Optimum levels of fertilizers and full weed and bird control programs were used. Netting was used to prevent lodging. Data on grain yield and its attributes were determined. Grain yield of tef was estimated to have risen for 35 years of breeding from 3425 to 4599 kg/ha. Biomass yield and kernel weight per main panicle were greater in newer cultivars, highly and linearly related to cultivar age, and positively and significantly correlated to grain yield. Number of spikelets per panicle is also greater in newer cultivars and significantly and positively correlated with grain yield. Improved plant height, panicle length and kernels per panicle were a feature of most modern genotypes. However, no change occurred in harvest index and 100-kernel weight. Results of a stepwise regression analysis of grain yield on selected yield components revealed that biomass yield was the single most important yield attribute, which accounted for 56.7% of the variation in grain yield.     

稻穗枝梗结实特性的研究

连续三年对66个水稻品种考种分析发现,水稻品种间一次枝梗数及其着粒数差异不大,二次枝梗数差异大,而着粒数较稳定.每穗粒数与一、二次枝梗数密切相关.二次枝梗数对每穗粒数和空秕率的增加起主导作用,一次枝梗数对空秕率有一定的抑制作用.每穗空秕率与二次枝梗数有关,还与品种的遗传特性有关.由于二次枝梗籽粒有两段灌浆现象,如遇不利因素,可导致空秕率增多.增加单位面积总粒数,保持较高结实率,在一定范围内增加每亩穗数已是水稻大面积丰产栽培的一条重要途径.因此,育种工作者可将一次枝梗着粒较多,二次枝梗空秕率较低的穗型作为选择高产品种的形态指标.     

Genetic potential to improve seed and forage yield simultaneously in smooth bromegrass under water deficit conditions

This study was conducted to assess genetic potential of smooth bromegrass for water stress and to identify the association among different seed and forage production related traits. Thirty-six genotypes were clonally propagated and evaluated in the field under two moisture environments (normal irrigation and water stress) during 2013–2015. High variation was observed among genotypes for all of the measured traits. Water stress had negative effects on seed yield and its components and reduced genotypic variation of measured traits. On average, water stress reduced seed and forage yield by 38 and 14%, respectively. Genetic coefficient of variation for seed yield and its components was higher under stress, providing opportunities for a greater selection differential. The estimates of heritability were higher in normal condition than water stress condition for all of the evaluated traits, which is advantageous for successful selection. Moreover, the majority of seed yield components had higher heritability estimates than seed yield. The higher heritability estimates of some seed yield components, compared to SYP, suggests a potential for indirect selection. The results showed that selection for both forage and seed yield is possible simultaneously in normal irrigation as well as in water stress environment. Genotypes 7, 8, 26 and 27 had high forage yield, while genotypes 23 and 27 had high seed yield under both normal irrigation and water stress condition. Three genotypes ranked among the top three for both seed and forage yield and under both normal irrigation and water stress condition. They are promising parents for further use in developing improved cultivars by cross-breeding.     

Variation in pod production and abortion among chickpea cultivars under terminal drought

The effect of terminal drought on the dry matter production, seed yield and its components including pod production and pod abortion was investigated in chickpea (Cicer arietinum L.). Two desi (with small, angular and dark brown seeds) and two kabuli (with large, rounded and light coloured seeds) chickpea cultivars differing in seed size were grown in a controlled-temperature greenhouse, and water stress was applied by withholding irrigation 1 (early podding water stress, ES), 2 (mid-podding water stress, MS) or 3 (late-podding water stress, LS) weeks after the commencement of pod set. In addition, the pod and seed growth of well-watered plants was followed for the first 19 days after pod set. Growth of the pod wall followed a sigmoid pattern and was faster in the desi than in the kabuli cultivars, while no difference was found in early seed growth among genotypes. Time of pod set affected the yield components in all treatments with the late-initiated pods being smaller, having fewer seeds per pod and smaller seeds, but no significant difference between pods initiated on the same day on the primary and secondary branches was observed. Early stress affected biomass and seed yield more severely than the later stresses, and in all stress treatments secondary branches were more affected than primary ones. Pod production was more affected by early stress than by late stress, regardless of cultivar. Pod abortion was more severe in the kabuli than in the desi cultivars, but final seed size per se did not appear to be a determinant of pod abortion under terminal drought conditions. The data indicated that the production and viability of pods was affected as soon as water deficits began to develop. The results show that pod abortion is one of the key traits impacting on seed yield in chickpeas exposed to terminal drought and that irrespective of differences in phenology, kabuli types have greater pod abortion than desi types when water deficits develop shortly after first pod set.     

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 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.