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Introgression of disease resistance genes from Arachis kempff-mercadoi into cultivated groundnut 总被引:1,自引:0,他引:1
Arachis kempff‐mercadoi is a wild species from the section Arachis. All kempff‐mercadoi accessions originate from the Santa Cruz province of Bolivia and they represent Arachis species with the A genome. From molecular analysis it was found that although cultivated A. hypogaea is made up of A and B genomes, A. kempff‐mercadoi may not be as closely related to it as are some of the other A genome species. Arachis kempff‐mercadoi is of interest because it has multiple disease resistance. It was crossed with a Spanish A. hypogaea cultivar which is susceptible to foliar diseases and to the insect pest Spodoptera litura. The success rate of the cross A. hypogaea (2n = 40) ×A. kempff‐mercadoi (2n = 20) was very low, but it could be increased by culturing immature seeds in vitro. Although the hybrids were triploids, a few fertile pollen grains were obtained due to the formation of restitution nuclei in the F1 plants. Interspecific derivatives at the BC2F2 generation were scored for early leaf spot, late leaf spot and to Spodoptera damage. Screening results showed that 29% of the derivatives had both early and late leaf spot resistance and that less than 5% of the derivatives had resistance to both the foliar diseases and to Spodoptera. 相似文献
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A detached leaf technique was used to evaluate components of resistance to both early and late leafspot caused by Cercospora arachidicola Hori and Cercosporidium personatum (Berk, and Curt.) Deighton, respectively, for F2 plants of two peanut (Arachis hypogaea L.) crosses (FESR 5-P2-B1 /PI 269685 and PI 35068Q/GP-NC 343), No negative correlations were obtained when comparing components of resistance to early leafspot with components of resistance to late leafspot, indicating that the resistances are inherited independently. A small number of F2 plants had greater partial resistance to both leafspots than their parents when evaluated by an index including percent necrotic area, latent period and sporulation. Broad sense heritabilities of resistance components were moderate to high (0.4 to 0.8) for the F2 populations. A visual sporulation rating scale was significantly correlated (0.8 to 0.9) with conidia per lesion and conidia per necrotic area. The data suggest that peanut cultivars resistant to both leafspots can be developed. 相似文献
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花生褐斑病和网斑病田间混发流行过程及其产量损失研究 总被引:2,自引:1,他引:1
通过田间小区人工接种试验,分析比较了花生褐斑病和网斑病单独及混合发生的流行过程及对花生产量损失的影响。结果表明,在病害混发初期,病害间无明显的相关性,随着病情加重,病害间的负相关性逐渐增大并达到显著水平,说明病害间有明显的抑制作用。在不同生育期接种发病情况有所差异,在开花初期和盛花期接种,褐斑病和网斑病的病情较重,而在开花末期接种的病情较轻,但都能表现病害间的抑制作用。病害混发时造成的产量损失小于各病害单独造成损失之和,对白沙1016和四粒红接种2种病菌,病害混合发生所造成产量损失约为各病害单独引起损失之和的77.2% ~ 85.7%和76.1% ~ 79.6%。在不同生育期接种2种病菌,2个品种产量的损失均随着侵染时期的推迟而逐渐降低。 相似文献
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花生网斑病(peanut web blotch),由花生亚隔孢壳菌(Didymella arachidicola)引起,病原菌又称花生茎点霉(Phoma arachidicola)或派伦霉(Peyronella arachidicola),在我国南北的各大花生产区均有发生,已成为生产上严重的叶部病害。为筛选产孢效率高、致病力强的菌株,研究病原菌进化机制和环境适应性,从来自不同地区的花生网斑病叶片样本中分离病原菌菌株,研究分生孢子及致病力差异。结果表明,18个菌株中YY187的产孢时间最短,22℃黑暗条件下燕麦琼脂培养基培养7 d即可产孢;菌株YY187和NY206产生的分生孢子器数量显著多于其它菌株;采用孢子悬浮液接种花生叶片,供试所有菌株均可造成叶片发病,其中菌株LY128和YY187在供试18个菌株中致病力相对较强。因此,综合评价产孢效率更高、致病力更强的本地菌株YY187适合作为花生抗网斑病研究的材料。 相似文献