春小麦结实特性对穗粒数的影响

试验以19个春麦品种为材料,试图探讨影响春麦穗粒数的生育阶段。结果表明,小花数多是穗粒数多的必要不充分条件;受精前的退化小花数相对来说要少于受精败育数和成胚后籽粒的退化数,也即受精前的退化小花数并不是限制穗粒数的主要因子;增加小花数同时减少小花的退化、减少受精败育数和成胚退化数是现阶段提高春麦穗粒数的关键。对于穗粒数多于40粒的品种减少小花数的退化提高可育小花数是增加穗粒数的关键;对于穗粒数在30￣40粒之间的品种减少成胚后籽粒的退化是提高穗粒数的关键;对于穗粒数低于30粒的品种,要增加受精前的小花数,同时要针对不同的品种,采取措施减少受精败育数或成胚后籽粒的退化数才能有效地提高穗粒数。     

小麦结实粒数、粒重和品质的小穗位和粒位效应

 【目的】研究小麦不同小穗位和粒位的穗结实粒数、粒重和品质变化规律。【方法】通过田间试验系统研究穗结实粒数相近,粒重和品质不同的3个小麦品种的结实粒数、粒重和品质的小穗位和粒位效应。【结果】3个小麦品种不同小穗位籽粒结实粒数、小穗千粒重、粒重、蛋白质含量、干面筋、沉降值、吸水率、稳定时间、评价值和软化度均呈现二次曲线变化趋势分布,第1粒位、第2粒位和第3粒位的粒重及品质也随小穗位的变化呈二次曲线形式,表现出籽粒发育的近中优势。第1粒位和第2粒位的粒重相近,都高于第3结实粒位;第2粒位增产潜力较大,是粒重变化的主要因素;临优2018和临优2069第2粒位,临优145第1粒位的蛋白质含量、干面筋和沉降值较高且变异较大,增质潜力较大,是品质变异的主要因素。【结论】在小麦育种和栽培中,对于每小穗最多结实3粒籽粒的品种,应尽量减少小花位数,来保持小麦籽粒品质的稳定性和一致性。     

氮肥处理对春小麦穗粒数形成阶段的影响

为研究氮肥对小麦穗粒数形成中不同发育阶段的影响,以穗粒数和结实率有差异的3个春小麦品种为材料,拔节期进行追肥,设置3个氮肥处理.结果表明,N1处理下3个品种的穗粒数均较其他两个氮肥处理下的穗粒数高.开花期增施氮肥能够延长小花分化的时间,增加小花分化的数量,减少受精成胚退化率,从而提高穗粒数.     

春小麦穗粒数调控途径

对１９７５～１９９２年有关穗粒数试验资料，进行逐步回归分析，明确东北春小麦穗粒构成因素对穗粒数的作用关系，并提出东北北部春小麦主产区春小麦穗粒数的调控途径：调整生育期进程，在多小穗基础上，提高小穗结实率是增花增粒和充分发挥北部主产区春小麦产量潜力的关键．关键词     

春小麦穗分化不同阶段对小穗数的影响

为了解春小麦穗分化的不同阶段对小穗数的影响,以小穗数有差异的5个小麦品种为材料,对其穗分化各个阶段的天数与总小穗数进行通径分析,结果表明:尽量加快伸长期、单棱期的分化速率,缩短这2个分化时期的时间、延长二棱期分化的天数是提高春麦总小穗数的途径。     

秸秆全量还田对冬小麦不同小穗位和粒位结实粒数和粒重的影响

 【目的】研究小麦玉米秸秆连续全量还田对小麦穗部不同小穗位和粒位结实粒数及粒重变化的影响。【方法】通过设置3年定位试验研究小麦玉米秸秆全量还田对小麦不同小穗位结实粒数、粒重的小穗位和粒位的影响效应。【结果】小麦玉米秸秆连续全量还田提高了小麦的公顷穗数、穗粒数、千粒重和产量。各处理小麦不同小穗位结实粒数、小穗重、小穗平均单粒重均呈现二次曲线变化趋势,不同粒位的粒重也随小穗位的变化呈二次曲线形式。结实小穗越多、各小穗结实粒数或单粒重差异越小,空间分布模拟曲线的弧度越平缓。秸秆还田提高了小麦主茎穗和分蘖穗的结实小穗数与小穗结实粒数,降低了不孕小穗数,且下部小穗的结实粒数增加幅度较大;秸秆还田还提高了小麦不同粒位的单粒重,以第3、4粒位提高幅度较大。【结论】小麦玉米秸秆连续全量还田提高了小麦不同小穗位的结实粒数和粒重,进而提高了籽粒产量。     

寒地水稻秕粒形成基础的研究Ⅰ剪叶与剪穗对水稻小穗结实的影响

本文通过盆栽的方法对19个水稻品种(系)在花期进行剪叶与剪穗处理,结果表明减少库容对降低秕粒率的效果不如减源对增加秕粒率的效果大;剪库增加粒重,而剪源则降低粒重.品种间对剪源与剪库的反映不尽相同.     

氮磷施用量对冬小麦小穗粒位结实粒数和粒重的影响

观察分析了氮、磷肥不同施用量对冬小麦不同小穗的不同粒位结实粒数和粒重的影响。结果表明,冬小麦灌浆期,多施氮肥或只施氮肥不施磷肥,有利于形成全部小穗粒数。在氮肥和磷肥配合施用的基础上多施磷肥,能够促进1、2粒位粒重的增加;在氮磷肥配合施用的基础上多施氮肥,有利于促进3、4粒位粒重提高,即氮肥对高粒位粒重有促进作用。1、2粒位粒数和粒重对产量影响不大,3、4粒位粒数和粒重直接引起产量差异,要提高产量必须提高3、4粒位粒数及其粒重。     

春化时长对半冬性小麦品种圣麦20穗粒数的影响

为了研究不同长度的春化时间对小麦穗粒数的影响,以圣麦20为试验材料,设置23～40 d的春化时间梯度进行春化时长对小麦穗粒数的影响研究。结果表明,圣麦20在4℃条件下完成正常生长发育所需的最短春化时间为26 d,其中春化时间26～32 d时分蘖与结实很少;春化时间在33～40 d时,圣麦20主分蘖的小穗数随春化时间的延长呈先上升再下降的趋势;春化38 d的植株生成的小穗数最多,而春化时间为36 d的植株产生的总穗粒数最多。该试验对于研究春化时长影响小麦小穗数及穗粒数,进而影响产量具有重要的意义。     

不同基因型冬小麦穗粒数与粒重生理差异分析

为分析不同穗型冬小麦籽粒建成的生理差异,以大穗基因型(JS)、小穗基因型(XS)和中穗基因型(JM22)冬小麦品种为材料,测定籽粒形成期和灌浆期器官干物质积累、蔗糖含量和蔗糖相关代谢酶活性、籽粒灌浆特性以及成熟期穗粒数和粒重等指标.结果表明:1)冬小麦穗粒数和粒重基因型间差异显著;2)大穗基因型冬小麦从四分体时期到成熟...     

稀植栽培条件对春小麦旗叶与穗部性状影响的研究

以 11个春小麦品种为试验材料 ,稀植栽培处理条件下 ,研究了旗叶与穗部两个性状 ,并进行了产量效应析。结果表明 ,稀植处理延长了旗叶功能期 (0 .7～ 2 .4 d) ,增加了旗叶长、宽和叶面积 ,显著程度因品种而异 ;穗粒数、穗粒重、千粒重随稀植处理密度的降低 ,呈增长趋势 ,稀植对穗粒数与穗粒重的影响远大于对千粒重的影响 ;根据稀植效应分析 ,将供试品种分为 3种类型 ,一类为耐稀植型 ,包括东农 12 2、东农 12 4、龙麦 2 6、东农 12 5 ;一类为稀植型 ,包括东农 12 3、龙麦 15、东农 97- 4 0 5 6、龙麦 2 0、龙麦 2 9及克丰 6号 ;另一类为非稀植型 ,仅龙辐 10号属此类型。     

Raised bed planting promotes grain number per spike in wheat grown after rice by improving spike differentiation and enhancing photosynthetic capacity

The yield of wheat in wheat–rice rotation cropping systems in the Yangtze River Plain, China, is adversely impacted by waterlogging. A raised bed planting (RBP) pattern may reduce waterlogging and increase the wheat yield after rice cultivation by improving the grain number per spike. However, the physiological basis for grain formation under RBP conditions remains poorly understood. The present study was performed over two growing seasons (2018/2019 and 2019/2020) to examine the effects of the planting pattern (i.e., RBP and flat planting (FP)) on the floret and grain formation features and leaf photosynthetic source characteristics of wheat. The results indicated that implementation of the RBP pattern improved the soil–plant nitrogen (N) supply during floret development, which facilitated balanced floret development, resulting in a 9.5% increase in the number of fertile florets per spike. Moreover, the RBP pattern delayed wheat leaf senescence and increased the photosynthetic source capacity by 13.9%, which produced more assimilates for grain filling. Delayed leaf senescence was attributed to the resultant high leaf N content and enhanced antioxidant metabolism. Correspondingly, under RBP conditions, 7.6–8.6% more grains per spike were recorded, and the grain yield was ultimately enhanced by 10.4–12.7%. These results demonstrate that the improvement of the spike differentiation process and the enhancement of the leaf photosynthetic capacity were the main reasons for the increased grain number per spike of wheat under the RBP pattern, and additional improvements in this technique should be achievable through further investigation.     

Novel and favorable genomic regions for spike related traits in a wheat germplasm Pubing 3504 with high grain number per spike under varying environments

Grain number per spike(GNPS) is a major factor in wheat yield breeding.A new wheat germplasm Pubing 3504 shows superior features in spike traits.To elucidate the genetic basis of spike and yield related traits in Pubing 3504,282 F2:3 families were generated from the cross Pubing 3504×Jing 4839,and seven spike and yield related traits,including GNPS,spike length(SL),kernel number per spikelet(KPS),spikelet number per spike(SNS),thousand-grain weight(TGW),spike number per plant(SNP),and plant height(HT) were investigated.Correlation analysis indicated significant positive correlations between GNPS and spike-related traits,including KPS,SNS,and SL,especially KPS.A genetic map was constructed using 190 polymorphic simple sequence repeat(SSR),expressed sequence tag(EST)-SSR,and sequencetagged-site(STS) markers.For the seven traits measured,a total of 37 quantitative trait loci(QTLs) in a single-environment analysis and 25 QTLs in a joint-environment analysis were detected.Additive effects of 70.3%(in a single environment) and 57.6%(in a joint environment) of the QTLs were positively contributed by Pubing 3504 alleles.Five important genomic regions on chromosomes 1 A,4 A,4 B,2 D,and 4 D could be stably detected in different environments.Among these regions,the marker interval Xmag834–Xbarc83 on the short arm of chromosome 1 A was a novel important genomic region that included QTLs controlling GNPS,KPS,SNS,TGW,and SNP with stable environmental repeatability.This genomic region can improve the spike trait and may play a key role in improving wheat yield in the future.We deduced that this genomic region was vital to the high GNPS of Pubing 3504.     

Relation between grain weight and falling number in soft spring wheat

The relation between 1000 grain weight and falling number in soft spring wheat varieties and lines is studied in years with a different temperature regime, precipitation amount, and time of its fall. Differently directed correlations (from weak negative to weak positive) between 1000 grain weight and falling number are established.     

不同基因型烟草农艺性状配合力分析

利用杂种优势是提高烤烟产量和改进品质的重要途径之一,配合力育种是杂种优势利用的主要育种手段之一。采用NCⅡ交配设计,对9个烤烟品种和1个白肋烟(TN90)进行5×5杂交,对10个亲本和25个F1的一些主要性状的配合力和遗传力进行分析,扩展了杂交组合对亲本的选择,为烤烟杂交育种正确选用亲本提供依据。     

小麦籽粒灌浆性状的配合力研究

以 6× 6双列杂交的F1～F3 及亲本为试材 ,对籽粒灌浆持续期和籽粒灌浆速率进行配合力分析。结果表明 ,籽粒灌浆性状的GCA (一般配合力 )和SCA (特殊配合力 )均方达显著水平 ,说明籽粒灌浆性状的遗传受基因加性效应和非加性效应共同作用。随世代推进 ,基因加性变异在总遗传变异中的比重逐渐加大。世代与GCA、SCA的互作极显著。F1与F2 、F3 的GCA、SCA相关不显著 ;F2 与F3 的GCA表现基本一致。在进行籽粒灌浆性状的家系育种时 ,应考察F2 及以后世代的亲本配合力及组合     

A major and stable QTL for wheat spikelet number per spike validated in different genetic backgrounds

The spikelet number per spike (SNS) contributes greatly to grain yield in wheat. Identifying various genes that control wheat SNS is vital for yield improvement. This study used a recombinant inbred line population genotyped by the Wheat55K single-nucleotide polymorphism array to identify two major and stably expressed quantitative trait loci (QTLs) for SNS. One of them (QSns.sau-2SY-2D.1) was reported previously, while the other (QSns.sau-2SY-7A) was newly detected and further analyzed in this study. QSns.sau-2SY-7A had a high LOD value ranging from 4.46 to 16.00 and explained 10.21–40.78% of the phenotypic variances. QSns.sau-2SY-7A was flanked by the markers AX-110518554 and AX-110094527 in a 4.75-cM interval on chromosome arm 7AL. The contributions and interactions of both major QTLs were further analyzed and discussed. The effect of QSns.sau-2SY-7A was successfully validated by developing a tightly linked kompetitive allele specific PCR marker in an F_2:3 population and a panel of 101 high-generation breeding wheat lines. Furthermore, several genes including the previously reported WHEAT ORTHOLOG OF APO1 (WAPO1), an ortholog of the rice gene ABERRANT PANICLE ORGANIZATION 1 (APO1) related to SNS, were predicted in the interval of QSns.sau-2SY-7A. In summary, these results revealed the genetic basis of the multi-spikelet genotype of wheat line 20828 and will facilitate subsequent fine mapping and breeding utilization of the major QTLs.     

不同穗型小麦品种小花发育与结实特性研究

以９７鉴１、杨麦１５８和河南８６７９为代表基因型,研究了特大穗型、大穗型和小穗型小麦品种在小花发育与结实特性上的差异。结果显示,小麦小花的化动态符合二次曲线方程模式,小花的退化动态符合一次方程模式,不同穗型品种在方程参数上有明显区别。特大穗型小麦小花分化速率快每穗分化小花数多,形成的中孕小花数和结实粒数量最多。不同穗型小麦的小穗结实率、小花结实率和可孕花结实率均为穗型越大,结实率越高,其中以可孕花结实率的级差最为明显。不同穗型小麦的强势位小花在结实特性上差异较小,但弱势位小花依穗型不同有明显的级差。特大穗型和大穗型小麦在幼穗分化后期输入穗中的干物质相对较多,穗茎比较高,因而穗中较高的干物质输入是大穗形成的物质基础。