番椒疫病菌Phytophthora capsici之有性與無性後代遺傳之比較

Genetic Comparison of Sexual and Asexual Reproduction of Phytophthora capsici

王志耕(C. K. Wang) ； 梁啟源(C. Y. Liang) ； 朱秋欣(C. H. Chu) ； 林玫珠(M. J. Lin)

《植物病理學會刊》 20卷3&4期 (2011/12) Pp. 98-107

https://doi.org/10.6649/PPB.201112_20(3_4).0005

摘要

番椒疫病菌是番椒及其它農作物的一種重要病原菌。在遺傳學方面，對這種病原菌在有性及無性生殖上的瞭解卻非常有限。本研究將對番椒疫病菌A1和A2分離株的游走子後代，與A1和A2分離株配對後的卵孢子後代，在菌落形態及生長速度上加以比較。我們觀察到A1和A2分離株的游走子後代在菌落形態及生長速度上相當一致，而且每個分離株的無性生殖後代之間，也看不出有何變異。然而，從A1和A2分離株配對後的卵孢子後代間，卻可觀察到相當大的菌落形態及生長速度上的變異。實驗中，兩個卵孢子分離株的無性生殖後代，在菌落形態及生長速度上持續顯現出變異。結果證實，番椒疫病菌是二倍體的假說，並指出有性生殖後的無性生殖後代的持續變異，於卵菌綱是一種普遍的現象。

關鍵字

番椒疫病菌 ； 有性後代 ； 無性後代 ； 菌落形態 ； 生長速度

並列摘要

Phytophthora capsici is an important pathogen of pepper and numerous other agricultural crops. Very little is known about the genetics of sexual and asexual reproduction of this pathogen. In this study, colony morphology and growth rate of zoospore progenies of A1 and A2 isolates of Phytophthora capsici were compared with those of oospore progenies resulted from the pairing of A1 and A2 isolates. Colony morphology and growth rate of zoospore progeny of A1 and A2 isolates were relatively uniform and not much variation was observed among asexual progeny of each isolate. However, considerable variation was observed among oospore progenies, resulted from pairing between A1 and A2 isolates, in both colony morphology and growth rate. Asexual offspring of two oospore isolates tested continue to display variation in colony morphology and growth rate among zoospore isolates. Our results support the hypothesis that species of Phytophthora are diploid and suggest that continuous variation in asexual generation following sexual reproduction may be a general phenomenon in Oomycetes.

並列關鍵字

Phytophthora capsici ； sexual reproduction ； asexual reproduction ； colony morphology ； growth rate