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201.
Genetic Variability for Grain Yield and Protein Content in Barley and Its Modification by Net Blotch 总被引:1,自引:0,他引:1
Protein content, yield and 1000-grain weight of healthy and net blotch-diseased plants were studied in a diallel cross programme concerning nine different varieties of barley (Hordeum vulgare L.). F1 hybrids and their parents were grown in the field in two randomized block design experiments each with three replications (three inoculated and three non-inoculated plots). General and specific combining abilities were determined for yield, protein percentage, 1000 grain weight, protein yield, and non-protein yield. A high genetic variability for the traits studied was observed. Non-protein yield and 1000-grain weight decreased significantly in inoculated plants where protein yield was not affected. Significant general and specific combining abilities were observed for all traits. Values for general and specific combining abilities were, in some cases, significantly modified by net blotch of barley. This indicates that attention must be paid to the danger of drawing conclusions in quantitative genetics studies dealing with both diseased and healthy plants. 相似文献
202.
Summary Diallel crosses were made between 15 tomato genotypes with varying performance under a low energy regime. It appeared that differences between genotypes for 11 vegetative and generative plant characters are determined mainly by additive genetic variation. For breeding cultivars adapted to low energy conditions, crossing genotypes with a high GCA for weight of trusses and fruits (WTF) and genotypes with a high GCA for weight of vegetative plant parts (WVP) seems most promising. Complications may arise from the negative correlation between GCA values for WTF and WVP, and the strong positive correlation between GCA values for fruit number and WTF, causing small fruits. 相似文献
203.
The objective of this study was to quantify the genetic variability and determine the inheritance of Al tolerance in lucerne
(or alfalfa) using a 4-parent diallel mating design. Regrowth root length (RRL), along with root length (RL) and total root
length (TRL), was measured to indicate relative Al stress response using a hydroponic system in a 3 μM Al solution at pH 4.5. A diallel analysis indicated the significance of general combining ability (gca) variance for RRL but not the specific combining ability (sca) variance; the same result was obtained for TRL but not for RL. For both RRL and TRL, genetic variance appeared to be more
important than the environmental variance. For RRL, a strong but non-significant correlation was indicated between parental
performance and their gca effects; while mid-parent heterosis and/or over-dominance were detected, as associated with the expressed sca effects in several combinations. These results suggest the complex genetic nature and expression of Al tolerance in the 4-parent
diallel crossing system tested. Al-tolerant parent, GAAT‘S’, was the most promising parent, conferring the highest gca effects for RRL as well as for other two characters. The existence of significant gca variance in RRL may also suggest the feasibility of improving Al tolerance through enhanced root regrowth using phenotypic
recurrent mass selection to pyramid desirable Al-tolerant genes, focussing on parental lines and/or elite individual plants
expressing long regrowth roots. 相似文献
204.
To overcome the cross-breeding barriers between the cultivated tomato Lycopersicon esculentum and the ‘peruvianum-complex’, hybrid production ability (HPA) and pistillate-parental differences were investigated. As a criterion of HPA, the number of germinated ovules per fruit (GPF) was used. GPF was expressed as GPF = OPF × GPO, where OPF is the number of ovules per fruit, and GPO is the proportion of germinated ovules to total ovules obtained. The interspecific crossing between nine varieties and three ‘peruvianum-complex’ accessions revealed that the cultivars ‘Sekaiichi’,‘Ponde Rooza’ and ‘Early Pink’ showed quite high and stable GPF over the years, but the cv.‘Best of All’ produced no hybrids. Variance analysis for GPF, OPF and GPO, and their correlation with seven sexual organ morphological traits and three fruit morphological traits were performed. These results indicated that choosing both the pistillate parents with wider reproductive organs for high OPF and appropriate environmental conditions for high GPO might be significant for enhancing GPF in interspecific crossing. 相似文献
205.
206.
大豆亲本品种数量性状的配合力分析 总被引:4,自引:0,他引:4
采用6个大豆亲本双列杂交设计,研究亲本及F_1、F_2的配合力.各性状的一般和特殊配合力方差分析多达显著水平.一般配合力效应表现较好的有豫豆6号和郑8431.在F_1和F_2中同一性状不同组合或同一组合不同性状间的特殊配合力效应具有显著差异.在不同世代中根据遗传力的大小,应对不同性状进行选择.单株粒重遗传力较低,不易在早期世代选择. 相似文献
207.
Prospects for hybrid breeding in winter triticale: II. Relationship between parental genetic distance and specific combining ability 总被引:1,自引:0,他引:1
Significant relative midparent heterosis (MPH%) for grain yield in triticale (×Triticosecale Wittm.) has generated interest in the development of hybrid cultivars. The objectives of this study were to (i) examine the association between parental genetic distance (GD) and specific combining ability (SCA), (ii) investigate the existence of genetically distant heterotic groups in elite germplasm, and (iii) draw conclusions for future hybrid breeding in winter triticale. Genetic distance between 61 lines was estimated, based on 93 polymorphic simple sequence repeat (SSR) marker loci and 10 AFLP (amplified fragment length polymorphism) primer‐enzyme combinations (PEC). Agronomic data of 206 F1 crosses and their 61 parental lines grown in six German environments were published recently in a companion study. Correlations were made between SCA for grain yield, number of spikes/m2, 1000‐kernel weight and number of kernels per spike with GD estimates of the 56 female and five male parents (testers). Principal co‐ordinate analyses (PCoA) based on SSR data revealed no distinct subgroups in the germplasm. Correlations between GD and SCA were low for all traits (|r| ≤ 0.31), which hampers the prediction of SCA from molecular data. A multi‐stage procedure is recommended for future hybrid breeding in triticale by applying a pragmatic approach for the grouping of germplasm following the early history of hybrid breeding of maize. 相似文献
208.
Yang Zhuping 《Euphytica》1997,95(3):253-258
Following anther culture of various F1 hybrids of indica restorer (R) lines/wide compatible varieties (WCVs) and japonica R lines/WCVs, the homozygous diploid plants
(2n) generated were test-crossed with indica WA type cytoplasmic-genetic male sterile (CMS) line Zhanshan 97A (WA), indica
testers Nanjing 11 and Nante, japonica BT CMS line Hanfeng A (BT), and japonica testers Balilla and Akihikari to identify
widely compatible restorer lines. The results of this study showed that among the diploid pollen plants generated from F1 hybrids of indica R lines/WCVs, 36.7% and 64.7% possessed normal fertility restoration ability (rate of seed-setting > 80%)
to Hanfeng A and Zhanshan 97A, respectively. 71.3% and 32.3% had normal fertility restoration ability to Hanfeng A and Zhanshan
97A, respectively, in diploid pollen plants derived from the japonica R lines/WCVs F1's anther culture. Several widely compatible R lines were selected from anther culture of F1 hybrids of indica R lines/WCVs and japonica R lines/WCVs. These widely compatible R lines derived from diploid pollen plants
showed good wide compatibility and restoration ability both to WA and BT type CMS lines. Strong standard heterosis of major
agronomic traits and yield traits was observed in F1 test-crosses of widely compatible R lines with Hanfeng A and Zhanshan 97A. The wide compatibility in widely compatible R
lines H17, H158 and H281 was studied by a set of three-way crosses. Segregation of the fertile plants with seed-setting rate
> 70% and semi-fertile plants with seed-setting rate > 69.9% agreed with a ratio of 1:1, indicating that wide compatibility
in these widely compatible R lines is governed by a pair of major genes.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
209.
水稻籽粒蛋白质、游离氨基酸含量的配合力与杂种优势分析 总被引:6,自引:2,他引:6
利用两组5×5双列杂交,以 Griffing模型Ⅰ分析籽粒蛋白质、游离氨基酸含量的配合力与杂种优势表现。结果表明:1.蛋白质、游离氨基酸含量均受加性和非加性基因效应的共同作用,但蛋白质以加性效应为主,游离氨基酸以非加性效应为主;2.蛋白质不存在显著的胞质效应,而游离氨基酸则存在极显著的胞质效应;3.蛋白质杂种优势较小,其最强的组合超中亲优势值仅为13.75%,而游离氨基酸存在强大的杂种优势,最高的组合可达155.17%;4.蛋白质、游离氨基酸一般配合力间存在极显著线性关系,在一般配合力改良上可同步进行; 5.京香1号、培矮64、IR58、Mcp231-2具有较高的一般配合力和较大的特殊配合力方差,可作为优良亲本利用。 相似文献
210.
Summary In Trinidad, maize (Zea mays L.) is primarily harvested in the immature stage as green ears for human consumption. The purchase of popular imported hybrid seed has become a substantial component of the economic inputs of maize production. The objectives of this study were to investigate combining abilities and heterotic patterns among available open-pollinated varieties and to assess correlations among five important traits: time to silking, plant height, grain yield, ear size, and marketable ears per hectare. General combining ability was significant for all traits. Specific combining ability was significant for all traits except ear size. Three intervarietal crosses showed moderate levels of heterosis (10–27%), and several yielded similarly to the control hybrids, Pioneer X304 and Pioneer 3078. The cross Acid Soil Tolerant 1991 SA-3 X ICTA Farm Corn was selected as the most suitable base population for mass selection. Phenotypic and genotypic correlations among the five traits studied were all positive and significant. Populations which flowered early were shorter and yielded less than the late flowering and taller populations and population crosses included in this study. 相似文献