Inheritance of nut and kernel traits in almond (Prunus amygdalus Batsch)

Summary An almond breeding program was initiated in 1966 to develop improved cultivars for arid conditions with irrigation. Nut and kernel traits were evaluated for almond parents and progenies. Highly significant parent/progeny correlation coefficients (0.7–0.9) were found for shell hardness, percentage of kernel, in-shell (nut) and kernel weight, kernel length and width, as well as kernel color and outer shell retention.Double kernels and kernel thickness had low parent/progeny correlation coefficients. Shell hardness and percent kernel were highly correlated, as were shell hardness and outer shell retention, percent kernel and outer shell retention, and kernel width and nut weight.All but two of the evaluated traits (kernel thickness and percent doubles) appear to be highly heritable with mostly additive gene action, although some degree of dominance appeared to be involved in percent kernel, shell hardness and percent doubles.Contribution No. 185-E from Agricultural Research Organization, Israel.     

Mass selection for kernel depth in early maize

Summary Effectiveness of mass selection for kernel depth in an early maize (Zea mays L.) synthetic, i.e. NDSAB, was evaluated in eight North Dakato environments. Four cycles of selection for deeper kernels were evaluated for grain yield and associated traits by using corresponding randomly selected subpopulations of NDSAB to adjust out inbreeding effects on selected subpopulations. General combining ability (GCA) effects of selected subpopulations also were evaluated for these traits.Subpopulations selected from one to four cycles for deep kernels were reciprocally crossed to corresponding randomly selected subpopulations in a factorial mating design. Subpopulations, selfed subpopulations, and subpopulation crosses were evaluated for yield and associated traits. Subpopulations selected for deep kernels generally had deeper kernels, higher yields, heavier kernels, more kernel rows per ear, and lower test weights than corresponding randomly selected subpopulations. Differences in GCA effects among selected and unselected subpopulations generally corresponded to differences between selected and unselected parental subpopulations. Inbreeding effects from selfing were observed for all traits, but no average heterosis was detected when subpopulation crosses were compared to parental subpopulations. Reciprocal differences were observed for all traits except kernel depth, but these differences were inconsistent relative to whether deep kerneled females made superior hybrids to unselected females.Results supported the use of mass selection for kernel depth as a means of grain yield improvement in the short term for NDSAB. However, negative associations of kernel depth with test weight may restrict long term use of this procedure.Journal Article No. 1505 of the North Dakota Agric. Exp. Stn., Fargo     

Candidate traits for index selection in choice of oil palm ortets for clonal propagation

Summary The objective of the study was to examine the usefulness of: principal component scores (PC), factor analysis cum stepwise regression identified traits (FASR) and selected traits based on their higher heritabilities and genetic correlations to the objective traits (HGC); as selection traits in a desired gains selection index (Yamada et al., 1975) to improve objective traits (oil yield, kernel oil yield, height increment, bunch index and leaf area ratio) as compared to those based on all the observed traits (AO); in selecting oil palm ortets for cloning.Based on the required selection intensities (i^*) to achieve the desired gains AO indices having smaller i^*'s were most efficient followed by PC, HGC and FASR indices. Expected selection response (1/i^*), however, is expected to increase with additional selection traits. As such HGC (bunch number, kernel to fruit and mesocarp to fruit) and FASR (mesocarp to fruit, fresh fruit bunch yield, fruit to bunch and average bunch weight) indices would be useful as they achieved expected selection responses close to AO indices with a small number of traits and would also minimise the contribution of highly correlated traits to sampling errors. The results also suggested considering selection indices for only two objective traits-oid yield and kernel oil yield-instead of all five objective traits in which case screening of impracticably large populations is needed to obtain desired genetic gains.     

Recurrent selection for seed quality traits in an opaque-2 maize population

Summary The aim of this research was to evaluate the response to phenotypic recurrent selection for four seed quality traits, i.e. protein content, dye binding capacity, tryptophan content, and specific weight, in a modified opaque-2 population of maize (Zea mays L.). Changes in other agronomic traits were also studied. Four selection cycles, using as selection criterion an index constructed from the four seed quality traits, were completed on an individual plant basis. The material from each cycle and from testerosses of each cycle with a homozygous opaque-2 tester was grown for two consecutive years to evaluate the progress due to selection. The results showed that four cycles of recurrent selection induced sizeable variations among cycles for all selected traits. The rate of progress for the four seed quality traits was nearly linear. Further-more, theldata show that improvement in seed-protein related traits had no negative effects on grain yield and kernel weight, when evaluated as the mean performance of testerosses. There was also no appreciable alteration in the other agronomic traits caused by selection for seed quality traits.     

Differences in reciprocal crosses of maize inbred lines diverse for protein content

Summary Forty-two crosses and their reciprocals in maize (Zea mays L.) involving inbred lines highly diverse for protein content were evaluated in four environments. Data were recorded on crude protein content of grain, protein yield, grain yield, 1000 kernel weight, dry matter content of ear at harves,, days to 50% slking, plant height, ear height, and early vigor. No significant variation due to reciprocal differences was observed for protein content and early vigor. For all other traits the variance component due to reciprocal x environment interactions was significant while the variance component due to reciprocal differences was significant only for kernel weight, dry matter content of ear, plant height, and ear height. The variance components due to nuclear differences and their interactions with environments were always highly significant and larger than the components due to reciprocal differences and reciprocal x environment interactions. The instability and low magnitude of reciprocal differences indicated that it might be difficult to exploit them commercially. However, seeing the presence of reciprocal differences for most of the traits studied, the evaluation of breeding materials for these differences seems to be important.The research work was supported by the Deutsche Forschungsgemeinschaft, Sonderforschungsbereich 142.     

Inheritance and relationships of important agronomic traits in almond

The inheritance of 16 important agronomic traits and its relationship were studied for four years in a population of 167 almond [P. dulcis (Mill.) D.A. Webb] seedlings obtained from a cross between the French selection ‘R1000’ (‘Tardy Nonpareil’ × ‘Tuono’) and the Spanish cultivar ‘Desmayo Largueta’. For some traits (blooming and leafing date) descendants segregated between the value of both progenitors, meanwhile for others the mean of the offspring was lower (bloom density, productivity and ripening date) or higher (in-shell/kernel ratio and double kernels). As expected, kernel bitterness and self-incompatibility behaved as monogenic traits. Some important correlations between traits were detected. The implications of the transmission and the correlation of these traits in the breeding programmes are discussed.     

Multivariate Extension of Griffing's Diallel Analysis

Diallel-cross designs have been used extensively in plant and animal breeding programs. In most cases, multiple traits are measured in the study, but the analyses are performed on each trait separately. The objective of this paper is to provide an alternative multivariate procedure so that the combining abilities among traits can be evaluated simultaneously and the interaction of combining ability and traits can be tested statistically.
Numerical example is provided from data of a rice study. Three characters, panicles per plant, percent sterility, and 100 kernel weight were used in the analysis. Results showed that some parental lines with greater combining abilities in one trait may not be so good in another trait. Also certain crosses may be better for one trait but not necessarily as good for other traits.     

Genetics of morphological traits in wild wheat,Triticum turgidum var.dicoccoides

Summary The mode of inheritance, linkage groups, and chromosomal location of 23 morphological and 4 biochemical traits were characterized in the wild tetraploid emmer wheat,Triticum turgidum var.dicoccoides. These traits were described and their mode of inheritance was determined by their segregation in four F₂ populations derived from crosses between four var.dicoccoides accessions and a tetraploiddurum cultivar. Linkage groups among the genes encoding for these traits were determined or postulated, and their chromosomal location was deduced by linkage to previously located genes. The genetic control of the following traits was characterized and is first reported here: black keel; hairy leaf sheath; hairy auricles; hairy rachilla; hairy kernel brush; obtuse flag leaf; and curved neck/peduncle. The linkage data indicated that developmentally-related genes tended to occur in clusters.     

Selection for white kernel color in the progeny of red/white wheat crosses

Summary Data are presented which support early generation selection for white kernel color in the progeny of red/white kernel wheat crosses which are segregating at 12 or more loci for yield (or any other trait of interest). The optimum generation for selecting white kernels is determined by the frequency of seeds produced with the potential to produce plants having desired quantitative alleles from both parents, and by the frequency of white kernels produced. The F₂-produced seed (F₃ embryo) is shown to be the optimum generation for selecting white kernels, given that 12 or more loci are segregating for a quantitative character such as yield. When the red parent is a 2 or 3 loci red genotype, selection among F₄-produced seed for white kernel color may be desirable when 5 or fewer genes are segregating for the second trait. The results have direct application for all highly heritable, recessive, sporophytic traits.Contribution from the Cornell Agricultural Research Station, Cornell Univ., Ithaca, NY 14853. Paper No. 723. Research supported by Hatch project 419     

优质蛋白玉米籽粒性状的遗传效应

选用8个胚乳性状差异显著的优质蛋白玉米(QPM)自交系, 采用Griffing I交配设计组配, 通过对亲本、F₁和F₂的鉴定, 探讨主要籽粒性状的遗传效应和杂种优势, 为有效利用热带硬质QPM种质改良、扩增我国温带QPM种质以及QPM籽粒性状改良和硬质QPM品种选育提供依据。结果表明, 籽粒百粒重、百粒体积、胚乳修饰度和籽粒密度在F₁和F₂代都表现一定的正向杂种优势; 胚乳修饰度在F₁代存在正反交差异, 母体效应明显; 4个性状的F₂代表型值与中亲值的相关性最大; 百粒重和百粒体积主要受母体效应控制, 基因效应以显性效应为主; 胚乳修饰度主要受种子直接效应控制, 基因效应以加性效应为主; 籽粒密度主要受母体效应控制, 基因效应以加性效应和显性效应同等重要。这4个籽粒性状的细胞质效应均较小, 主要受核基因控制。     

Genetic parameters for nut and kernel traits in macadamia

Data from a trial of 40 cultivars clonallyreplicated over five locations were used to estimatebroad-sense heritability and genetic and phenotypiccorrelations for important nut and kernel traits inmacadamia (Macadamia integrifolia and M.tetraphylla). Location averages for each cultivarwere available from 4 to 10 years after planting fornut mass, kernel mass, kernel recovery, percentage1^st grade kernels and percentage whole kernels,with individual tree measurements only available forone year. Heritability estimated from locationaverages was inflated for all traits due tounderestimation of the phenotypic variance. Un-confounded estimates of individual broad-senseheritability, obtained by combining information fromboth data sources, was high (H = 0.63) fornut and kernel mass, and kernel recovery, moderatefor percentage whole kernels (H 0.30) and low for percentage 1^stgrade kernel (H 0.20). There waslittle interaction between cultivar and location orage; however, for percentage 1^st grade and wholekernels, there were large 3-way and 4-wayinteractions. The only strong genetic correlation wasbetween nut and kernel mass (r _g = 0.80). Theimplications of the results for cultivar selection andbreeding programs are discussed.     

转基因抗虫棉种子品质性状的遗传效应及相关性分析

 采用二倍体种子数量性状遗传模型和统计分析方法,分析了陆地棉9个亲本和30个杂交组合的子指、种仁率、仁壳比、蛋白质含量、油分含量和棉酚含量等种子物理性状和营养品质性状的遗传效应、遗传率和遗传相关性。结果表明,所有棉子品质性状均受种子直接遗传效应和母体遗传效应的共同控制,种仁率还受到细胞质效应的影响。子指和仁壳比以母体显性效应为主,蛋白质含量以显性效应为主,油分含量和棉酚含量以母体加性效应为主。遗传相关性分析表明,棉子物理性状和营养品质性状间的显性遗传相关均达到极显著水平,其中子指与蛋白质含量呈极显著显性正相关,子指与油分含量和棉酚含量呈显性负相关。种仁率和仁壳比与3个棉子营养品质性状间的母体遗传相关均达到了极显著水平。     

Multiple‐line cross QTL mapping for grain yield and thousand kernel weight in triticale

Grain yield and its component trait thousand kernel weight are important traits in triticale breeding programmes. Here, we used a large mapping population of 647 doubled haploid lines derived from four families to dissect the genetic architecture underlying grain yield and thousand kernel weight by multiple‐line cross QTL mapping. We identified 3 QTL for grain yield and 13 for thousand kernel weight which cross‐validated explained 5.2% and 48.2% of the genotypic variance, respectively. Both traits showed a positive phenotypic correlation, and we found two QTL overlapping between them. Full two‐dimensional epistasis scans revealed epistatic QTL for both traits, suggesting that epistatic interactions contribute to their genetic architecture. Based on QTL identified in our results, we conclude that the potential for marker‐assisted selection is limited for grain yield but more promising for thousand kernel weight.     

基于全基因组关联分析解析玉米籽粒大小的遗传结构

玉米籽粒大小是产量重要构成因子之一,也是受多基因调控的复杂数量性状,挖掘玉米籽粒大小相关性状的关键调控基因,将有助于提高玉米的产量。本研究以212份优良玉米自交系为材料,于2018年和2019年分别对粒长、粒宽和粒厚进行测定,并结合均匀分布于玉米基因组的73,006个单核苷酸多态性(single nucleotide polymorphism,SNP)标记进行全基因组关联分析。基于FarmCPU算法,在玉米的10条染色体上检测到47个与籽粒大小相关性状关联的SNP。结合B73玉米自交系籽粒发育的动态时空转录数据,在显著SNP标记的连锁不平衡区域内,共检测到58个与籽粒大小相关的候选基因,其编码的蛋白与多种蛋白存在互作关系,参与并调控多个与籽粒发育密切相关的生物学过程。本研究为解析玉米籽粒发育的分子调控机制,改良籽粒大小和提高作物产量提供了新的参考。     

Amplified fragment length polymorphism as a tool for molecular characterization of almond germplasm: genetic diversity among cultivated genotypes and related wild species of almond,and its relationships with agronomic traits

Amplified fragment length polymorphism (AFLP) analysis is a rapid and efficient method for producing DNA fingerprints and molecular characterization. Our objectives were to: estimate genetic similarities (GS), marker indices, and polymorphic information contents (PICs) for AFLP markers in almond cultivars; assess the genetic diversity of almond cultivars and wild species, using GS estimated from AFLP fingerprints and molecular characterization; and facilitate the use of markers in inter-specific introgression and cultivar improvement. The genetic diversity of 45 almond cultivars from Iran, Europe, and America, were studied assaying 19 primer combinations. In addition, several agronomic traits were evaluated, including flowering and maturity times, self-incompatibility, and kernel and fruit properties. Out of the 813 polymerase chain reaction fragments that were scored, 781 (96.23%) were polymorphic. GS ranged from 0.5 to 0.96, marker indices ranged from 51.37 to 78.79, and PICs ranged from 0.56 to 0.86. Results allowed the unique molecular identification of all assayed genotypes. However, the correlation between genetic similarity clustering as based on AFLP and clustering for agronomic traits was low. Cluster analysis based on AFLP data clearly differentiated the genotypes and wild species according to their origin and pedigree, whereas, cluster analysis based on agronomic data differentiated according the pomological characterization. Our results showed the great genetic diversity of the almond cultivars and their interest for almond breeding.     

粒重基因TaCwi-A1等位变异在黄淮麦区小麦品种(系)中的分布及功能分析

为探讨小麦粒重基因TaCwi-A1等位变异TaCwi-A1a和TaCwi-A1b在育种实践中的应用价值,首先利用TaCwi-A1功能标记对539份黄淮麦区小麦品种(系)进行分子检测,确定各供试材料的等位变异类型,从而获得TaCwi-A1a和TaCwi-A1b 2种等位变异的分布频率。对审定品种、参加区试品系以及自育品系进行了千粒质量(3个不同生长环境)及粒长、粒宽和籽粒面积(1个生长环境)测试分析,比较TaCwi-A1a和TaCwi-A1b等位变异籽粒表型性状的差异性。结果表明,在539份黄淮麦区小麦资源中TaCwi-A1a的分布频率为65.03%,TaCwi-A1b的分布频率为34.97%,TaCwi-A1a的分布频率明显高于TaCwi-A1b。籽粒表型性状分析表明,无论是审定品种,还是参加区试品系和自育品系,在3个生长环境下,TaCwi-A1a基因型材料的千粒质量均值都显著高于TaCwi-A1b;TaCwi-A1a基因型材料的粒长和粒宽均显著高于TaCwi-A1b。进一步验证了TaCwi-A1a等位变异的籽粒表型性状增效功能,说明其对粒重及其构成要素是优异的等位变异。此外,本研究鉴定了黄淮麦区中TaCwi-A1等位变异的分布情况,为亲本选配提供了参考。     

陆地棉品种间杂种的种仁油分和氨基酸成分的遗传分析

用双列分析的方法研究了陆地棉(Gossypium hirsutum L.)4个品种及其杂种 F_1的种仁油分和氨基酸成分的资料,分析了杂种优势的表现和遗传效应,并估算了棉子性状间的简单相关系数。F_1的种仁含油率表现正的平均优势(4.75%),种仁氨基酸总量表现负的平均优势(-3.60%)。这两个性状的显性方差(H_1、H_2)都远大于加性方差(D),表明它     

Divergent full-sib recurrent selection for germination at low temperature in a maize population

Summary Four cycles of divergent full-sib recurrent selection for the ability to germinate at low temperature were conducted in a maize (Zea mays L.) F₂ population. The selection criterion was the high (H) or the low (L) value in algebraic terms of the difference (DG) between germination percentage at 9.5°C (G9.5) detected 19 days after sowing and germination percentage at 25°C (G 25) seven days after sowing; both traits were evaluated in a controlled environment (germinator). Direct and correlated responses estimated during the course of selection were in accordance with those evaluated at the end. Selection for H led to populations with higher DG values, while the reverse was noted for L; differences between H and L populations increased in successive selection cycles, though divergence tended to level off. Selection for H also resulted in higher G 9.5 (day 19), shorter germination time and more flinty kernels, while selection for L led to responses in the opposite direction as well as to a lower G 9.5 detected 37 days after sowing (i.e. at the end of germination). In contrast, responses were negligible for G 25 and varied erratically from one cycle to another for kernel weight.Abbreviations DG (G 9.5–G 25) - FS full sib - GI germination index - G 9.5 germination percentage at 9.5°C - G 25 germination percentage at 25°C - H high DG value in algebraic terms - KT kernel type - KW kernel weight - L low DG value in algebraic terms     

37个玉米新品种（组合）耐旱性评价

为评价37个玉米新品种（组合）的耐旱性潜力,采用4种控水处理对玉米植株性状和产量性状进行了分析评价。结果表明,水分胁迫对穗长、秃尖长、行粒数、百粒重、ASI和单株产量6个性状有显著或极显著影响。水分胁迫使玉米品种抽丝散粉间隔期延长,秃尖变长,结实率降低,行粒数减少,籽粒变小,百粒重下降,单株产量降低。应用模糊数学隶属函数法综合评价分析,‘帮豪玉509’、‘忠玉9号’、D36、BH0310和D30综合耐旱性较强,D23、D3、D26和BH3404综合耐旱性较差。