Genetic nature, stability, and improved virulence of hybrids from protoplast fusion in Beauveria
Genetic nature, stability, and improved virulence of hybrids from protoplast fusion in Beauveria
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DOI：
10.1007/bf00170102
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发表时间：
1996-07-01
影响因子：
3.6
通讯作者：
Riba, G
中科院分区：
文献类型：
--
作者：
Couteaudier, Y;Viaud, M;Riba, G
通过与杀虫产毒菌株硫白僵菌的杂交，获得了两种不同的球孢白僵菌遗传改良菌株，以更有效地防治nubilalis Ostrinia和Leptinotarsa decemlineata。双营养突变体之间的原生质体融合导致一些稳定的原生营养融合产物的恢复。球孢白僵菌28与硫芽孢白僵菌2杂交得到的一个杂种（FP 8）对12芽孢白僵菌和nubilalis的低毒力得到增强。硫芽孢杆菌与高致病性球孢芽孢杆菌147杂交获得的融合产物25显示，对nubilalis的LT（50）降低了3天。对原始野生菌株、亲本突变菌株和融合产物的基因组dna进行了9种探针-酶组合的Southern blot杂交。在5个杂交品种中均观察到亲本系的加性带带或独特带带模式，表明它们是重组和/或部分二倍体。在融合产物FP 25中从未观察到指示亲本基因组的RFLP标记的结合。融合产物FP - 8和FP - 25在昆虫寄主传代后毒力的稳定性和分子结构的稳定性表明，原生质体融合的无性遗传重组可能为昆虫病原真菌生物防治效果的遗传改良提供了一种有吸引力的方法。
Genetic improvement of two different strains of the entomopathogenic fungus Beauveria bassiana for more effective control of Ostrinia nubilalis and Leptinotarsa decemlineata was obtained by crosses with the insecticidal toxin-producing strain Beauveria sulfurescens. Protoplast fusion between diauxotrophic mutants resulted in the recovery of some stable prototrophic fusion products. The low levels of virulence of the wild type strain B. bassiana 28 isolated originally from L. decemlineata were enhanced both on L. decemlineata and O. nubilalis for one of the hybrids obtained (FP 8) from the cross B. bassiana 28 x B. sulfurescens 2. Fusion product 25 obtained from the cross between B. sulfurescens and the highly pathogenic strain B. bassiana 147 showed a three-day reduction in the LT(50) towards O. nubilalis. Southern blot hybridization with nine probe-enzyme combinations were conducted on genomic DNAs from the original wild strains, parental mutant strains, and fusion products. Additive banding patterns or unique banding pattern of either parental strain was observed in five hybrids, indicating their status as recombinant and/or partially diploid. Combination of RFLP markers indicative of both parental genomes was never observed with fusion product FP 25. The stability of the virulence following passage through insect-host and stability of molecular structure for the fusion products FP 8 and FP 25 suggest that asexual genetic recombination by protoplast fusion may provide an attractive method for the genetic improvement of biocontrol efficiency in entomopathogenic fungi.