小麦籽粒灌浆期的早代选择

籽粒灌浆期（ＧＦＰ）可能是一个有用的生理学选择性状，它能够影响谷类作物的籽粒产量．本研究以６个遗传多样性的春小麦群体为试材，评估了ＧＦＰ的遗传力，确定了长ＧＦＰ和短ＧＦＰ的选择效应．在Ｆ２代进行选择并在Ｆ３代通过田间试验对选择后代进行重复评价．试验于１９９０年在尼泊尔的Ｒａｍｐｕｒ进行，采用正常播种和晚播两种处理．播期对ＧＦＰ、籽粒产量、生物学产量、收获指数、百粒重有明显的影响．Ｆ２中长、短ＧＦＰ的选择对于鉴定Ｆ３代的长短ＧＦＰ是有效的，而且选择长的ＧＦＰ通常会获得较高的籽粒产量和生物学产量。长ＧＦＰ系的平均收获指数、百粒重高于短ＧＦＰ系．ＧＦＰ的遗传力估计值属于中高类型（０．５２－０．８６）。ＧＦＰ与籽粒产量、收获指数和百粒重均呈正的遗传相关，相关系数分别为０．５２－０．７９、０．５０－０．８０和０．５３－０．７２．结果表明．在早代选择长ＧＦＰ可以改良上述产量因子。     

小麦籽粒灌浆期的早代选择

籽粒灌浆期（ＧＦＰ）可能是一个有用的生理学选择性状，这能够影响谷类作物的籽粒产量，本研究以６个遗传多样性的春小麦群体为试材，评估了ＧＦＰ的遗传力，确定了长ＧＦＰ和短ＧＦＰ的选择效应。在Ｆ２代进行选择并在Ｆ３代通过田间试验对选择后代进行重复评价，试验于１９９０年在尼泊尔的Ｒａｍｐｕｒ进行，采用正常播种和晚播两种处理，播期对ＧＦＰ，籽粒产量，生物学产量，收获指数，百粒重有明显的影响，Ｆ２中长，短ＧＦＰ     

豆豉特用大豆几个性状与籽粒产量的相关分析

本文分析了10个特用大豆品种的几个生理性状与小区籽粒产量的相关性。结果表明:鼓粒初期叶绿素a、(a+b)含量与小区籽粒产量有显著的正相关,相关系数分别为0.7109、0.6799;光合速率、叶氮(％)、比叶重与小区籽粒产量的相关系数均不显著。通径分析表明:苗期和鼓粒初期的比叶重对小区籽粒产量有较大的负效应,开花期和鼓粒末期的比叶重对小区籽粒产量有较大的正效应。从24个因子中经逐步回归筛选得到一个含有6因子的回归模型:Y=4.0311+0.1625x_4+0.5569x_5-273.1188x_9-278.8875x_(10)+274.7645x_(11)-0.7925x_(10)用此模型模拟小区籽粒产量可靠性较好。     

中国南方大豆干物质积累、分配等生理性状与产量的关系

对73个生育期相近产量水平不同的南方大豆品种研究结果说明,籽粒产量与生物量及收获指数正相关,尤以后者更密切。鼓粒期茎叶比与收获指数显著相关,因而也与籽粒产量显著相关。初花期、结荚期等干物重与生物量显著相关,因而也与产量显著相关。作物生长率反映干物质积累的速度,与生物量及籽粒产量显著相关。叶质重、生殖生长期/营养生长期比值因分别与净同化率及收获指数相关而与产量显著相关。     

夏大豆植株碳氮化合物的消长及其对产量形成的影响

在北京田间试验的结果表明,夏大豆植株叶片全氮含量开花期较高,随后逐渐下降:叶片总糖及可溶性糖含量花芽分化期及鼓粒盛期前较高。结荚后单株荚数明显地受到叶片内全氮积累量的制约。籽粒的迅速生育导致叶片全氮及总糖积累量急剧减少。籽粒产量及籽粒积累氮量与开花、鼓粒期叶片全氮积累量呈极显著正相关。花前追施氮肥显著地提高了叶片全氮及总糖积累量,从而提高了籽粒产量。氮素营养可能是夏大豆荚、粒形成的限制因子。     

大豆叶片净光合速率、转化酶活性与籽粒产量的关系

本文研究不同大豆品系（种）鼓粒期冠层叶片的净光合速率、转化酶活性与单株籽粒产量的关系。结果表明,不同大豆品系（种）的净光合速率、转化酶活性和籽粒产量均存在明显差异。大豆籽粒产量与叶片净光合速率之间呈显著正相关（ｒ＝０．５６６８）,而与叶片转化酶活性之间表现负相关,但不显著（ｒ＝－０．１７３３）。本研究筛选出两个高光效高产大豆品系９７０２和９２０８－５,它们的净光合速率比早熟１８号高光效对照品种分别提高１１．２９％和１９．２％,籽粒产量分别提高３３．４９％和２６．２５％。     

不同灌水方式对春大豆籽粒产量的影响

对春大豆始花期到鼓粒期进行灌溉技术研究结果表明 :不同的灌水量和时期 ,对大豆籽粒产量有明显影响。如灌水仅1次 ,在大豆结荚鼓粒初期灌水 ,增产较明显 ,如灌水 2次 ,应在始花期和鼓粒初期各灌水 1次 ,可将大豆产量提高到最高值。     

浅析灌水对大豆产量的影响

大豆是需水较多的作物，尤以分枝期到鼓粒期对水分要求最高。试验表明，大豆生育期间适当灌水，可明显提高大豆产量：开花期灌水。增产40．80％；结荚期灌水，增产52．19％；开花和鼓粒期各灌水一次，增产92．33％；分枝、开花、鼓粒期各灌水一次，增产155．77％；分枝、开花、结荚、鼓粒期各灌水一次，增产166．21％。从经济效益上看，开花期和鼓粒期各灌一次水，经济效益最高，其产投比达到6．87：1。     

不同生育期大豆去叶对生长发育的影响

通过对大豆不同生育时期摘除不同量叶片的研究表明：整个生育时期随着叶面积的损失量增大，大豆的单株有效荚数，有效粒数，籽粒增长强度及百粒重降低就越明显，在盛花期以前损失30%-50%的叶面积，对产量无明显影响，鼓粒期叶面积稍有损失，大豆产量就会明显降低。     

野生大豆结瘤固氮与叶片和籽粒含氮量的关系

17份野生大豆的盆栽试验结果指出,野生大豆在结瘤固氮方面存在着明显的基因型差异。花期根瘤数、根瘤鲜重和固氮酶活性与单株叶片含氮量呈显著或极显著的正相关,固氮酶活性与单株籽粒氮产量呈正相关,分枝期、花期、结荚鼓粒期的相关系数分别为0.401,0.478和0.512。     

大豆生育阶段研究——Ⅱ.大豆鼓粒期长度遗传

本研究选择大豆鼓粒期长度(SFP)不同的4个亲本配制8个组合,估测其F_1和F_2的6种SFP值。结果表明:同一组合不同SFP分级和同一分级不同组合的SFP杂种优势存在差异,F_1SFP的中亲优势率平均值为97.5％—99.5％。SFP遗传属于数量性状遗传,无母体效应存在,具有较广泛的遗传变异,F_2广义遗传力高于产量遗传力,可以作为育种后代选择指标,但在早期世代不宜采用。确定R_3—R_6为SFP时期,应用于高产育种的后代选择。     

High Carbon Requirements for Seed Production in Soybeans [Glycine max (L.) Merr.]

Abstract

In soybeans, increase in the dry weight of seed (IWS) during the seed-filling period (SFP) is nearly half that of the whole plant (IWP). Hence, the contributions of assimilate during SFP to seed growth in soybeans is apparently lower than that in other cereal crops. However, analysis of the assimilate budget for seed production based on dry matter could be misleading in soybeans because the carbon (C) contents of seed and that of other organs are different due to the differences in lipid and protein content and respiration loss in each organ results in underestimation of the C contribution to seed production. In field soybeans, irrespective of shading and thinning, IWS/IWP and harvest index (HIW) for dry weight were slightly lower than ICS/ICP and HIC for C, respectively. Of the ¹³C fed at the vegetative stage and early SFP, 3.4% and 16.4%, respectively were accumulated in the seed, 0.9% and 28.2%, respectively, in the pod shell and 26.8% and 37.8%, respectively were respired before maturity. Ninety-six percent of seed C was assimilated during the SFP. Respiratory loss of ¹³C fed at the early SFP was larger than that from ¹³C at the vegetative stage, showing that seed production requires much more C than leaf or stem growth. These results suggest that the difference in C contents between plant organs has little effect on the estimation of assimilate partition into soybean seeds based on dry matter, and high respiration loss for seed growth reduces the partition of dry matter into seeds.     

Identification of diverse germplasm lines for agronomic traits in a chickpea (Cicer arietinum L.) core collection for use in crop improvement

Utilization of exotic and diverse germplasm is needed to enhance the genetic diversity of cultivars. Genetically diverse lines provide ample opportunity to create favorable gene combinations, and the probability of producing a unique genotype increases in proportion to the number of genes by which the parents differ. Representative core collections (10% of the entire collection) have been suggested as a means to identify useful parents for crop improvement programs. The chickpea core collection (1956 accessions) was evaluated for 14 agronomic traits in two seasons to identify diverse agronomically superior chickpea germplasm. Season (year) and genotypic effects were significant for 13 of the 14 traits, while genotype × season effect was significant for 8 traits. The desi, kabuli, and intermediate type chickpeas differed significantly for days to maturity, basal secondary branches, pods per plant, seed yield, and 100-seed weight. In comparison to controls, 12 accessions flowered early, 15 produced greater seed yield, and 29 had greater 100-seed weight. Based on days to 50% flowering, pods per plant, seed yield, and 100-seed weight, 19 desi, 15 kabuli and 5 intermediate type chickpea germplasm lines originating from 10 countries were selected. The selected desi accessions produced 8.5% more seed yield and had 32% larger seeds than the control cultivar Annigeri while the selected kabuli accessions yielded at par with control L 550 but had 84% larger seeds. The 39 selected accessions and two control cultivars (Annigeri and L 550) were grouped by their first five principal components (PCs) into three clusters. Cluster 1 consisted of early maturing large-seeded kabuli types, cluster 2 early and late maturing desi types, and cluster 3 late maturing intermediate and kabuli types. Clusters 2 and 3 accessions had small to medium sized seeds. These accessions can be used in chickpea breeding programs to develop high yielding desi and kabuli cultivars with a broad genetic base.     

Effects of Selection for Yield Components on Grain Yield in Pearl Millet (Pennisetum typhoideum Rich.)

Abstract

Pearl millet (Pennisetum typhoideum Rich.) was selected for yield and yield components. Sub-populations selected for high value of grain yield, seed weight, panicle weight and productive panicles showed higher values of the selected characters than those selected for low values and the original population. The genetic gains were obtained and heritability values were estimated as 0.74, 0.84-, 0.65 and 0.50 for yield, seed weight, panicle weight and productive panicles, respectively. Genetic correlations between the yield and seed weight, panicle weight and productive panicles were calculated as 1.00, 0.89 and 0.75, respectively. Indirect selection for yield components improved grain yield. Grain yield was between 371 and 590 g m^?2. Accordingly, selection for yield components may be effective for improving grain yield.     

玉米自交系微小遗传差异对产量优势的贡献

对3个玉米自交系遗传差异不同的株系自交3代后株系间产量及相互间杂交优势进行分析。结果表明,同一自交系在遗传上存在微小差异的株系,产量水平及其产量构成因素仍然存在一定差异。自交系初始遗传差异越大,后代株系间的产量差异越大;初始单株遗传差异较小的两个玉米自交系昌7-2和郑58具有微小遗传差异株系间杂交组合的超中亲优势分别达到10.55%、4.77%,超高亲优势分别达到3.69%、3.94%。对杂交优势贡献主要来自行粒数,其次是千粒重。通过关联分析找出行粒数相关基因的SNP标记14个(-Log P4),千粒重相关基因的SNP标记3个(-Log P3)。在开放授粉的条件下,株系间微小遗传差异有利于提高亲本和杂交制种产量。     

硒肥对制种田玉米杂交种子活力及产量的影响

选取甘肃省3种基因型的玉米主栽品种(早熟、中熟和晚熟)亲本材料，在母本灌浆期喷施硒肥，在母本果穗子粒生理成熟(乳线大约在1/2位置)和完熟(乳线消失)时期测定秃尖长、出籽率、百粒重等产量构成因素，测试种子中硒元素含量和种子活力，分析外源调节物质“富硒叶面调节剂”对制种田玉米产量、子粒硒含量及种子活力的影响。结果表明，喷施有机硒肥对制种玉米部分产量构成因素有一定影响，不同基因型玉米秃尖长减少不显著，出籽率显著增加，显著提高种子中硒含量、种子发芽势和种子发芽率。     

大豆亲本及其杂交后代农艺性状与产量关系分析

以晋大52、晋大57及其杂交衍生的55个稳定后代品系为材料,研究了株高、分枝数、生育期等15个农艺性状与产量的遗传关系。通过主成分分析,将15个指标综合成为累计贡献率达85.81%的6个新指标;经多元线性逐步回归分析得出产量与主成分值之间的回归方程;用回归方程预测品种产量,方程估产的误差百分率绝对值除2、10、21、22、30、39、53号品系外,其余品系误差绝对值均低于10%;以主成分值为指标的聚类分析将57个材料聚为高产、中产、低产3类。结果证明主成分回归法可以应用于大豆产量相关性状的研究;总荚数、总粒数、主茎荚数、分枝数、叶绿素含量等指标对产量的影响较大;大豆的产量能力可通过研究不同性状间的差异水平来评估。     

大豆籽粒蛋白质含量早世代选择效果及其对产量和脂肪含量的影响

利用3个大豆杂交组合研究了F_2或F_3代根据单株蛋白质含量进行高、中、低分組选择的选择效果及其对产量和脂肪含量的影响;分析了蛋白质、产量、脂肪及蛋白十脂肪总量之间的遗传相关及相关遗传进度。结果表明:(1)不同杂交组合早世代蛋白质含量分组选择的效果不同。F_2或F_3分组选择的F_3或F_4组间蛋白质含量有一定重叠,但一般高组蛋白质含量高于中组或低组;(2)早世代蛋白质含量分组选择对脂肪含量影响较大,对产量则无显著影响;(3)蛋白+脂肪总量与蛋白质含量显著正相关,与脂肪和产量负相关不显著。以选择蛋白+脂肪总量估计的蛋白质含量相关遗传进度与直接选择的遗传进度相似;产量和脂肪的相关遗传进度有正有负但绝对值均很小。综上结果认为,早世代根据蛋白+脂肪总量进行选择较为合适。     

Association of growth dynamics, yield components and seed quality in long-term trials covering rapeseed cultivation history at high latitudes

Brassica oilseed yield trend has declined in Finland by over 20% during the last 15 years. Improved genetic yield potential of turnip rape (B. rapa L.) and oilseed rape (B. napus L.) can be better realised with increased understanding of yield determining processes under northernmost growing conditions. This study aimed at (1) determining the genetic improvements in seed yield, yield components, quality traits and duration of the main growth phases and (2) comparing all these traits in turnip rape and oilseed rape. This work is based on the dataset from long-term Official Variety Trials (1976–2006), covering the entire historically relevant period of rapeseed cultivation in Finland. The results indicated that number of seeds per square metre dominated production of high yields, while single seed weight was not correlated with yield. Over the years, seed yields were produced with very different combinations of seed numbers and weights, differing markedly between the two crops. While high seed numbers were required for production of superior seed yields, single seed weights were not particularly high. Environmental variation markedly affected seed yield, seed number per square metre and duration of flowering compared with its effect on single seed weight. Duration of flowering was, however, negatively associated with seed number. Even though seed weight was largely determined by genotype, no marked plant breeding improvements were identified, contrary to those in number of seeds per square metre, seed yield, oil content and oil yield. For oilseed rape the increase in seed yield (41%) was far higher than for turnip rape (19%) without being associated with a longer seed-filling phase and later ripening, but rather the contrary.     

蓝标型显性核不育小麦的特性及其F1杂种优势分析

为了使小麦显性太谷核不育基因Ms2在杂种小麦上得以利用,以创制的显性蓝粒附加系97-866为基础,转育成功8份不同基因背景的新不育系,并对这8个不育系的粒色和育性分离状况以及杂种优势进行了分析.结果表明,在这8个新不育系的后代中,蓝粒不育株占20.6%～23.8%,平均为22.3%;白粒非矮秆可育株占77.6%,其它类型仅占0.1%,表明蓝粒基因、Ms2和Rht10基因均位于附加染色体上,而且连锁紧密.但对性状不同轮回亲本,矮败蓝粒于的传递率有差异,部分轮回亲本间差异达到5%显著水平,同一轮回亲本在不同年份间对蓝粒不育株传递率的影响差异不显著.F1代杂种优势表现为既有超亲优势又有超标优势,筛选出3个杂交种的籽粒产量超过对照15%以上.