几个小麦品种单株产量的配合力分析

通过双列杂交方式,对6个小麦品种的单株产量进行了一般配合力和特殊配合力效应分析。结果表明,豫麦10号单株产量的一般配合力较高,除与西安8号的差异不显著外,与其它品种一般配合力效应间的差异均达极显著水平。在特殊配合力方面,豫麦10号与陕农7859、冀麦5418与偃师4号较高,与其它杂交组合单株产量的特殊配合力效应差异达显著或极显著水平。     

甜玉米产量配合力分析

将遗传差异较大的8份甜玉米自交系进行8×8完全双列杂交试验,分析了后代产量的配合力和遗传力.配合力方差分析结果表明:一般配合力、特殊配合力和反交效应都达到了极显著水平.对一般配合力效应值、特殊配合力效应值和反交效应值进行了估算.部分亲本杂交时,F1产量表现出显著的正反交差异.遗传力分析表明:广义遗传力较高,狭义遗传力偏低.     

冬小麦沉降值杂种优势测定和配合力分析

冬小麦沉降值的杂种优势表现和配合力的试验分析,结果表明:丰产亲本的一般配合力效应差异不显著,而优质亲本的一般配合力效应达到极显著差异,各组合的特殊配合力方差达到了显著水平。内乡188、豫展1号、豫麦34、多数性状的一般配合力都较高,平均优势正向优势的组合数远远小于负向优势,而超高优势均为负向优势,是理想的亲本材料。     

油葵不育系、恢复系产量性状配合力的评价

通过对油葵不育系、恢复系产量性状进行双列杂交分析,结果表明自交系间一般配合力和特殊配合力存在极显著、显著差异.F1的产量性状受亲本自交系的一般配合力和特殊配合力的共同影响,但一般配合力效应较特殊配合力的略大.自交系的一般配合力和特殊配合力间无明显相关关系.在杂交组合配制以及自交系的改良计划中,应首先在较高的一般配合力的基础上,同时要求有较高的特殊配合力方差.     

几个粳稻亲本农艺性状配合力的分析

采用5×7不完全双列杂交法配制了35个粳稻杂交组合,对9个农艺性状的配合力效应进行了分析。结果表明：9个性状的特殊配合力差异均达极显著水平;父本穗长、千粒重的一般配合力差异达极显著水平;母本株高、穗长、一次枝梗数、二次枝梗数、每穗实粒数、每穗总粒数、千粒重、单株产量的一般配合力差异达极显著水平。相关分析表明,单株产量的一般配合力与株高、一次枝梗数、二次枝梗数、每穗实粒数、每穗总粒数的一般配合力呈显著正相关。     

春小麦主要营养品质性状的配合力分析

本文对５个春小麦品种的蛋白质含量、赖氨酸、色氮酸、蛋氨酸含量进行了完全双列杂交的配合力分析。方差分析表明，除蛋氨酸的一般配合力外，其它品质性状的一般配合力和特殊配合力方差均达到了显著或极显著水平。依据一般配合力效应，特殊配合力效应及特殊配合力方差，讨论了亲本品种有关性状的遗传特点及其在育种中的作用。     

油葵自交系子实含油率性状配合力的鉴定

通过对油葵不育系、恢复系子实含油率性状进行双列杂交分析,结果表明自交系间一般配合力和特殊配合力存在极显著、显著差异.F1的子实含油率性状受亲本自交系的一般配合力和特殊配合力的共同影响,但一般配合力效应较特殊配合力的略大.自交系的一般配合力和特殊配合力间无明显相关关系.在组配高油杂交组合及高含油率自交系的改良计划中,应首先在较高的一般配合力的基础上,同时要求有较高的特殊配合力方差.母本自交系对杂交种的子实含油率影响较大.     

3个旱稻品种杂交配合力及其应用分析

选用1个传统农家旱稻品种和2个改良旱稻品种与国内外7个水稻品种进行不完全双列组配,获得21个杂交组合,对旱稻品种9个性状的配合力和遗传参数进行了分析研究.结果表明:传统农家旱稻品种的各性状有很高的一般配合力,改良旱稻品种一般配合力较低;改良旱稻品种虽然部分结合了传统农家旱稻的抗旱性和水稻的丰产性,但是传统旱稻中仍然有许多优良的基因有待挖掘利用.特殊配合力分析表明4个组合单株产量特殊配合力正向效应显著,主要源于单株总谷粒数、单株总实粒数、单株结实率和单株有效穗数的特殊配合力的显著正向效应.各性状遗传力分析表明,主茎穗长、株高有较高的狭义遗传力,适于早代选择;单株总谷粒数、单株总实粒数、单株产量、单株结实率和单株有效穗数的特殊配合力方差所占群体总方差比例均大于70%,所以应该在较晚的世代加以选择.     

家蚕若干数量性状配合力和遗传力研究

用9个家蚕品种组成5×4不完全双列杂交,估算家蚕10个数量性状的配合力和遗传力。结果表明:(1)各性状的一般配合力方差均达极显著,杂交组合间9个性状的特殊配合力达极显著水准;(2)同一品种在不同性状上一般配合力相对效应值差异明显;(3)对于不同的性状,一般配合力在品种间变动范围也不尽相同;(4)同一杂交组合在不同性状的特殊配合力相对效应值差异显著;(5)茧层量、茧层率、茧丝长、一蛾产卵量狭义遗传力较高;全茧量、缫折、解舒、解舒丝长较低,对NPV病的敏感性的狭义遗传力特低。     

水稻产量和抽穗期性状的配合力效应分析

采用同一套常规水稻品种作为父本,分别与两套不同的不育系进行测交,得到两套测交组合(Set1和Set2)。其中,Set1连续进行两季(雨季和旱季)种植试验,研究亲本材料的单株产量和抽穗期的一般配合力与特殊配合力效应.2个性状的一般配合力和特殊配合力方差均达到显著水平,表明它们受加性基因和非加性基因的共同控制.运用Griffing模型Ⅰ对一般配合力和特殊配合力方差变量进行比较分析.结果表明,在雨季时,Set2母本单株产量的一般配合力方差大于父本,特殊配合力的相对效应大于亲本一般配合力的相对效应;而在雨季和旱季时,Set1表现相反,抽穗期的特殊配合力相对效应大于亲本一般配合力效应,表明杂交后代抽穗期主要受特殊配合力效应的影响.在旱季中,母本一般配合力效应大于父本一般配合力效应;在雨季中,母本与父本一般配合力效应差异不显著.     

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.     

小麦有效穗数的遗传分析及其SSR分子标记

选择有效穗数有显著差异的3个小麦品种(品系)西农9814(P1)和西农953、西农9718(P2)为亲本,配制杂交组合(西农9814×西农953、西农9814×西农9718),采用P1、P2、F1、F四家系世代联合分析方法和SSR分子标记技术,研究小麦有效穗数的遗传效应及对其进行初步定位。结果表明:2个组合有效穗数性状的遗传均符合2对加性-显性-上位性主基因+加性-显性多基因模型。在西农9814×西农953组合,2对主基因的加性效应(d)近似相等,分别为-1.850、-1.831,多基因的加性效应为1.931;在西农9814×西农9718组合,2对主基因的加性效应分别为-2.984和-1.159,多基因的加性效应为2.393;2个组合的主基因遗传率分别为58.26%和54.23%,多基因遗传率分别为0和9.90%,环境方差分别占表现方差的41.74%和35.87%,说明小麦有效穗数以主基因遗传为主,也易受环境的影响;用400对SSR引物对亲本和有效穗数性状极端池进行筛选,性状标记Xgwm113、Xgwm368、Xgwm495在亲本和极端池之间表现多态性,用这3个标记检测F2群体的392个单株,通过线性回归分析...     

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.     

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.     

Field tests of the method of selecting barley in an artificial light culture for maximum grain number per spike

Individual selection of plants for spike size is carried out under controlled conditions at a high intensity of photosynthetically active radiation and 24-h irradiation. Barley lines singled out during growing in the field for 3 years were considerably more productive than the initial specimens due to an increased grain number per spike and 1000 grain weight. They did not differ from the initial specimens in grain protein content.     

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...     

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.     

巨穗小麦种质小穗数的染色体定位研究

巨穗小麦新种质材料是一具有茎秆粗壮、叶片短宽直立、穗大、粒大、结实率高等特点的种质资源。应用单体分析和双端体分析方法对"241"材料进行遗传学研究,结果表明,小麦新种质材料"241"的3A、1B、2B和6B染色体上具有控制小穗数的隐性基因,其中3A、1B和2B染色体上的基因表现为强效,6B染色体上的基因表现为弱效。通过双端体分析进一步将控制小穗数的基因定位到3AS、1BL和6BS上,其中3AS、6BS上可能具有控制"241"小穗数的新基因。控制"241"穗粒数和控制小穗数的基因可能存在一定的连锁关系。     

Perceived predation risk reduces the number of offspring songbirds produce per year

Predator effects on prey demography have traditionally been ascribed solely to direct killing in studies of population ecology and wildlife management. Predators also affect the prey's perception of predation risk, but this has not been thought to meaningfully affect prey demography. We isolated the effects of perceived predation risk in a free-living population of song sparrows by actively eliminating direct predation and used playbacks of predator calls and sounds to manipulate perceived risk. We found that the perception of predation risk alone reduced the number of offspring produced per year by 40%. Our results suggest that the perception of predation risk is itself powerful enough to affect wildlife population dynamics, and should thus be given greater consideration in vertebrate conservation and management.     

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。