花生主要数量性状相关遗传参数分析

对花生主要数量性状进行了相关遗传参数分析,结果表明：结果枝数、饱果数的相关遗传力大于小区籽仁产量的遗传力;饱果数对小区籽仁产量的遗传变异贡献率最大;饱果数、百果重、出米率对小区籽仁产量的直接作用较强。提示在花生高产育种中,应注重结果枝数、饱果数、百果重和出米率等性状的选择。     

国内报刊花生文摘

花生主要性状的遗传/王玉莹,唐桂英…∥中国油料.-1987,(4).-12-16 分析10个花生品种16个性状的变异系数,广义遗传力、性状间的相关性和性状的遗传进度的结果表明:(1)花生主要性状在不同品种中表现出很大的差异,这是由遗传基础和环境影响引起的。因而进行花生数量性状的改良是可行的。(2)花生各性状的广义遗传力具有较大的差异。总果数、饱果数、单株生产力、小区产量的广义遗传力相对较低、育种中需要进行多次选择;百果重、百仁重的遗传力     

爆玉米产量性状的遗传参数研究

本文根据37个爆玉米优良杂交种的田间试验结果,较为系统地研究了单株产量性状的遗传力、遗传变异幅度和遗传进度等遗传参数。结果表明,爆玉米产量性状的遗传改良效果既取决于性状的遗传变异幅度,又决定于该性状遗传力的大小。就本试验所涉及的基因型而言,以秃尖度、百粒重、轴重、单穗粒重和单穗重的遗传改良潜力较大,宜直接选择;行粒数次之,其他产量性状相对较低。育种实践中应积极拓宽性状的遗传变异,提高遗传力,以期达到育种目标要求的选择效果。     

花生主要经济性状遗传参数对单株产量的选择效果

本文估算了花生11个性状的遗传进度和选择指数等遗传参数。结果表明,性状间遗传力存在较大差异,应据此掌握各世代不同性状的选择标准。对单株产量的直接选择很重要,单株结果数是相关选择的关键性状,选择饱果数多、侧枝长的材料对单株产量也有一定的改良效果,选择时应予以重视,而百果重、百仁重不是产量的限制因素。花生育种应用选择指数方法进行综合选择比对单株产量单一性状直接选择的效率提高23.22％,应用前景广泛。     

玉米自交系主要农艺性状遗传参数的分析

对34份玉米自交系10个农艺性状遗传参数的分析表明，行粒数、穗重、穗粒重的遗传力和遗传进度较高，遗传变异范围广泛，直接选择的效果最佳。9种性状组合的间接选择对提高自交系穗粒重和穗重效果显著。     

天府花生主要经济性状遗传规律研究初报

经对8个“天府”型花生杂交组合及相应亲本材料7个性状的遗传规律研究表明:(1)亲本对杂种后代的影响较大,各性状中亲值(双亲均数,后同)对F1—3代的平均遗传力为58.34～87.66%;(2)除单株产量和总果数外,其余株高、总分枝数、百果重、百仁重,出仁率5个性状在世代间的遗传力都高,一般在50%以上,最高达96.28%;(3)F2—4代单株产量的遗传力、以及各性状对产量的相关遗传力都很低或不稳定,进行直接单株选择或间接单株选择均无意义。     

花生四个产量性状的不完全双列杂交分析

用8个花生品系及其组配的16个不完全双列杂交组合的F1～F4代，研究了单株果重、饱果数、百果重、出仁率4个产量性状的配合力、杂种优势和遗传力。结果表明：①4个性状在F1～F4各世代的配合力变异都极显著，且在F1代变异最小，单株果重和百果重在不同世代的配合力不一致；②杂种优势在出仁率上表现为负向优势，且世代间差异较小，在其他3个性状上则表现为正向优势，且在各世代表现不一致，F2、F3、F4代较F1代有不同程度的衰退；③单株果重遗传力较弱，各世代遗传力最大为0．4860（h^2 2,3），饱果数、百果重和出仁率遗传力较强，均达到显著或极显著，各世代遗传力最大分别为0．7416（h^2 2,3）、0．9359（h^2 3,4）和0．8693（h^2 3,4）。     

花生春秋播主要性状的遗传变异

以珍珠豆型花生为材料,研究春秋播条件下主要性状的遗传变异。结果表明,秋播条件下单株果数、果重,开花至成熟日数变异率较小,遗传变异系数高于春播,遗传力高于或与春播相近,遗传进度也高于春播,与春播单株果重呈正相关或显著正相关。秋播花生的百果重、百仁重、出仁率变异率小;百果重、百仁重与春播单株果重呈显著正相关;出仁率春秋播的遗传参数相近。在秋播条件下,可对上述这些性状进行严格选择。     

花生育种应用选择指数的研究

本文以两个杂交组合的260个株系为材料,研究了花生育种应用选择指数的问题,建立了含有单株产量、单株果数,单果重、饱果数和总分枝数五个不同性状组合的31个选择指数,分析了各性状对产量选择遗传进度的作用和重要性。结果指出,单株产量在花生的后代选择中是第一个重要经济性状,但必须重视单株果数和单果重两者的协调一致。逐项选择法、选择指数法和独立淘汰法三种不同选择方法的选择效率比较结果,选择指数法最为有效。选择指数法可用一个“值”,对产量和其它与产量有密切关系的性状进行综合评定,它无论在理论预期进度上还是在实际进度上都比对单株产量单一性状进行直接选择有更高的效率。     

花生主要数量性状与产量相关的初步研究

关于花生主要性状间相关性的研究,国内外研究者在早期(1930—1933)曾作过一些测定,近年国内甘信民等(1964,1974)对花生主要性状遗传力和相关性曾作过研究和分析,在相关性方面指出:(一)与产量呈极显著的正相关有饱果数、单株结果数。(二)单株结果数与饱果数、秕果数呈极显著的正相关,与百果重、百仁重呈极显著的负相关。(三)饱果数与总果枝数呈显著的正相关,与百果重、百仁重呈显著的负相关。(四)总果     

旱稻数量性状的遗传参数分析

从广义遗传力、遗传相关、遗传进度和选择指数等几个方面,分析了57份旱稻品种的株高、有效穗数、主穗长度、主穗粒数、千粒重、单株粒重和剑叶长/宽7个主要数量性状的遗传潜力和选择效果.分析结果表明：株高、剑叶长/宽、单株粒数、主穗长度、千粒重的广义遗传力较高,有效穗数、单株粒重的广义遗传力偏低;单株粒数、单株粒重、有效穗数3个主要产量构成因素的遗传变幅较大,在该群体中对这3个性状进行选择的潜力较大;产量性状中的单株粒数和千粒重与单株粒重本身均有一定的遗传潜力,预期遗传进度也较大,特别是单株粒数的预期遗传进度较大;单株粒重与单株粒数、千粒重间存在显著或极显著的遗传正相关,主穗长度与有效穗数间存在极显著的遗传负相关,因此可以通过提高单株粒数和千粒重来间断增加单株产量;用单株粒重与单株粒数、千粒重和有效穗数构成的选择指数进行综合选择,相对效率高达219.34%,比直接选择单株粒重提高了119.34%,显著高于对单株粒重的直接选择,因此采用这个指数对单株粒重进行间接选择效果较为理想.     

影响水稻株高和剑叶宽主效QTL对人工选择的响应

 利用粳稻Lemont导入籼稻特青背景构建的高代回交导入系和重组自交系群体,在北京和海南两地检测影响株高和剑叶宽的稳定表达的主效QTL,分析这些主效QTL在导入系和重组自交系群体的不同选择强度（5%、10%和20%）的极端群体中的等位基因偏离,研究不同性状的主效QTL对不同选择强度的响应及不同遗传结构群体对主效QTL人工选择响应的影响。结果表明,导入系的选择群体中所有主效QTL等位基因的偏离方向都使得供体等位基因频率增加,等位基因产生偏离的性状选择方向及供体等位基因的偏离方向与基因的加性效应方向完全一致,而重组自交系的选择群体中主效QTL等位基因的偏离既有供体等位基因增加的,也有等位基因降低的,两种群体中不同性状的主效QTL等位基因偏离与选择强度密切相关。通过比较不同群体结构的主效QTL定位及对选择响应的异同,发现一些假阳性QTL和在随机作图群体中漏检的QTL,强调作图群体QTL定位结果验证的重要性。鉴于不同群体、不同性状和不同主效QTL的选择响应特点,对不同主效QTL在基于常规表型选择和分子标记辅助选择回交育种中的利用价值及注意事项进行了探讨。     

Selection indices for improving selection efficiency in Indian mustard

In Indian mustard (Brassica juncea L. Czern & Coss), a major oilseed brassica crop, oil yield is the ultimate trait of economic value, which is determined by seed yield (SY) and oil content (OC). SY, the end product of many complex biological processes, is influenced by many traits, such as plant height (PH), branch number, siliqua number, seed weight, seed size and pod length. It is difficult to accurately select for high-yielding genotypes based exclusively on SY, neglecting other yield-determining traits in commercial breeding programs. Therefore, it is desirable for breeders to simultaneously improve several traits of economic importance, most of which are quantitative in nature. The purpose of the present study was to develop selection indices for simultaneous selection of multiple quantitative traits to enhance selection efficiency of the mustard breeding program of Punjab Agricultural University (PAU) located in Abohar, Punjab. A set of 487 diverse mustard genotypes, comprising germplasm accessions of Indian and European origin, advanced breeding lines, landraces, and cultivars, was evaluated using an alpha lattice design for 2 years (2015–16 and 2016–17) at the Regional Research Station of PAU, Abohar, District Fazilka (the major mustard-growing region of the Punjab state). Data on PH, main shoot length (MSL), number of primary branches (NPB), number of secondary branches (NSB), number of siliquae on main shoot (NSMS), siliqua length (SL), number of seeds per pod (NSP), 1000-seed weight (TSW), SY on a plot basis and OC were recorded. To compute selection indices, economic weights, as determined via path coefficient analysis, were assigned to major yield-determining traits. Out of eight recorded agronomic traits, four traits, viz., NSMS, TSW, NSB and NPB, had larger direct effects on SY than other traits, and hence were assigned relative economic weights of 0.60, 0.20, 0.12 and 0.08, respectively. Selection indices were computed using different combinations of traits via Kang_SASPath computer program. When seven traits were used in a selection index (PH, NPB, NSB, NSMS, SY, TSW and MSL; or PH, NPB, NSB, NSMS, SY, TSW and OC), expected genetic advance (GA)at 5% selection intensity was about the same (9.55; selection efficiency or SE = 163% compared with selection based on SY alone).The GA was 9.46 (SE = 161%)for five traits, viz., NPB, NSB, NSMS, SY and TSW; and 9.30 (SE = 159%)for four traits, viz., NPB, NSB, NSMS, and TSW. These GAs were compared with the GA for SY only, which was 5.90 (benchmark; SE = 100%). We concluded that simultaneous selection based on multiple traits was always more efficient than selection based on SY alone. As there was only a small difference between the GA based on four traits (SE = 161%) and GA based on seven traits (SE = 163%), we suggest that mustard breeders use the parsimonious combination of four traits, viz., NPB, NSB, NSMS, and SY, to enhance SY and, consequently, oil yield in mustard.     

玉米子粒性状种子和母体效应的遗传分析

采用二倍体种子遗传模型及其分析方法,以5个玉米自交系及其间配制的F₁,F₂,BC₁,BC₂世代为材料,研究了7个玉米子粒性状的直接效应、母体效应和细胞质效应。分析结果表明,除粒厚外,各性状的遗传均以母体加性效应为主,种子直接显性效应和母体显性效应较小,细胞质基因对各性状均无显著影响,而环境效应极显著。除粒长的直接显性效应与母体显性效应间的协方差外,直接效应与母体效应间的协方差均较小,且不显著。因此,通过母体植株的遗传表现可对这些性状进行有效的直接选择。S₂₂是改良粒重的优良亲本,而N_O1,N_O2,N_O3对改良粒重不利。各部位子粒百粒重的直接显性效应、母体加性效应、母体显性效应及机误均存在极显著正相关。在自交系选育过程中,直接选择粒较宽的分离类型,容易获得大粒的遗传材料,选择粒厚而宽的亲本组配杂交组合有利于提高F₁粒重。     

Comparison of selection methods among and within full-sibling progenies in Urochloa humidicola

Hybridization in the Urochloa humidicola breeding programme allowed to explore the genetic variability of the apomictic sources and, thus, to obtain new sexual and apomictic parents with compatible ploidy and/or superior progenies. However, given the high variability arising from crosses, there is a need to adopt efficient selection strategies among and within progenies. The aim of this study was to compare the selection methods among U. humidicola progenies with (t-BLUP) and without (BLUP) the weighting based on prediction error and subsequent selection within progenies by individual simulated (BLUP_IS) or optimal individual BLUP. We evaluated seventy-one U. humidicola full-sib progenies from biparental crosses between nine sexual and ten apomictic parents. The experiment was set up in an incomplete block design with 64 blocks of 15 plots each, consisting of individual plants. Seven consecutive cuts were made and the traits total dry-matter, leaf dry-matter and regrowth scores were measured. Genetic variance was expressive for all traits. The selection procedure among progenies of U. humidicula based on t-BLUP proved to be more advantageous regarding the use of BLUP not weighted by the prediction error, resulting in higher selection gains, taking as reference the optimal procedure of the individual BLUP. Furthermore, the use of BLUP_IS allowed an optimized selection of hybrids, allowing the breeder to explore with variable selection intensity the genetic variability within the selected full-sib progenies based on relative genetic merit.     

甘蔗家系经济性状遗传变异分析及综合选择

以17个甘蔗家系为研究对象,对各家系的株高、茎径、锤度、丛有效茎、丛重、锤重6个经济性状进行遗传参数分析,采用多性状综合选择指数法对该家系群体进行综合评价。结果表明:家系在株高、茎径、锤度、丛有效茎、丛重和锤重均达到极显著差异,6个性状的遗传力都较高(0.68~0.97);株高的遗传变异系数(14.25%)最大,锤度(4.12%)最小;通过综合选择指数、优良度和遗传增益评价出2个优良家系,粤糖00-236×赣蔗75-65和云蔗94-375×CP72-2086。     

引进甘蔗种质资源杂交后代适应性评价

通过对引进甘蔗种质资源24个杂交后代的的10个农艺性状进行主成分分析、回归分析与通径分析,科学评价引种甘蔗种质资源在广西本地的农艺性状表现,探究各农艺性状间的协同制约关系,为甘蔗种质资源的精准评价和杂交育种材料的科学选配提供理论依据。结果表明:(1)主要农艺性状变异系数为6.79%~29.44%,24个甘蔗种质在分蘖和蔗糖产量上有较大的遗传改良潜力。(2)主成分分析将这10个农艺性状凝聚成4个主成分,分别为产量因子、有效茎因子、糖分因子和出苗因子,贡献率分别是35.2%、16.5%、15.3%、12.1%,累计贡献率达到79.1%;(3)通径分析中各性状对糖产量的直接通径系数大小依次为:蔗茎产量(0.927)>蔗糖分(0.399)>单茎重(0.039)。表明:甘蔗品种(系)GUC23-1、GUC15-2、GUC23、GUC34、GUC25在广西的丰产性最优,在甘蔗引种和选育中,考虑将蔗茎产量、蔗糖分、单茎重作为主要选择性状。     

小麦籽粒性状的遗传效应分析及其育种策略

大粒性状对于小麦高产育种具有重要意义。为明确大粒型小麦新种质籽粒性状的遗传特性,以漯麦76（大粒型）和L529（小粒型）为亲本构建P₁、P₂、F₁、F₂、B₁和B₂共4个世代6个群体,利用SmartGrain软件获得籽粒性状数据,采用主基因+多基因混合遗传分析方法研究大粒性状的遗传规律。结果表明,千粒重的最佳模型为两对加性-显性-上位性主基因+加性-显性-上位性多基因遗传模型（MX2-ADI-ADI）,籽粒面积和粒长的最佳模型均为加性-显性-上位性多基因遗传模型（PG-ADI）,籽粒周长的最佳模型为两对加性-显性-上位性主基因遗传模型（2MG-ADI）,粒宽的最佳模型为两对加性-显性-上位性主基因+加性显性多基因遗传模型（MX2-ADI-AD）。综上,对大粒性状的选择,应采用“高粒重×高粒重”的组合配制方案构建F₂（单交）和B₂（大粒亲本回交）选择群体,多环境鉴定,以低代宽、高代严的选择标准,在高代对大粒性状进行选择。     

Agronomic performance of rice breeding lines selected based on plant traits or grain yield

Selection for yield per se has greatly contributed to yield improvement in many crops. It is expected that selection based on plant traits is more effective in increasing crop yield potential. This study was conducted to compare the effectiveness of trait-based and yield-based selection in increasing rice yield and to determine whether lines with ideotype traits have the potential to express higher yield under optimal crop management conditions. Lines were selected based on plant traits or on grain yield measured in a breeder's replicated yield trial. The main target traits for selection were plant height, leaf and panicle morphology, grain size, total dry weight, and grain-filling percentage. Yield performance of trait-based selection was compared with that of yield-based selection in an agronomic trial with optimum crop management for three seasons. Trait-based selection increased leaf area index and total dry weight but reduced spikelet number per m² and harvest index compared with yield-based selection. Consequently, selection based on plant traits did not increase grain yield compared with selection based on yield per se. In one of the three seasons, yield of trait-based selection was significantly lower than that of yield-based selection. Among all tested breeding lines, maximum yield was produced by yield-based selection and minimum yield came from trait-based selection. These results suggest that lines with ideotype traits did not express higher grain yield than lines selected based on yield per se under optimal crop management conditions, and yield-based selection was as effective in increasing rice grain yield as trait-based selection in the late generations of the breeding cycle.     

Forage peanut (Arachis spp.) genetic evaluation and selection

Forage peanut improvement for use in grass–legume mixtures is expected to have a great impact on the sustainability of Brazilian livestock production. Eighteen cloned Arachis spp. ecotypes were evaluated under clipping in a Brazilian Cerrado region and results analysed using a mixed model methodology. The objective was to estimate genetic and phenotypic parameters and to select the best ecotypes based on selection index applied on their predicted genotypic value. The traits of total dry‐matter (DM) and leaf DM yield presented moderate (0·30 <  < 0·50) to high (>0·50) broad‐sense heritability, in contrast to the low genetic variability in nutritional quality‐associated traits. Ecotypes of Arachis spp. contained average crude protein concentrations of 224 g kg^?1 DM in leaves and 138 g kg^?1 DM in stems, supporting the potential role of these species to overcome the low protein content in Cerrado pastures. The correlations between yield traits and traits associated with low nutritional value in leaves were consistently significant and positive. Genetic correlations among all the yield traits evaluated during the rainy or dry seasons were significant and positive. The ecotypes were ranked based on selection index. The next step is to validate long‐term selection of grass–Arachis in combination with pastures under competition and adjusted grazing in the Cerrado region.