KMnO4和H2O2刺激掘氏疫霉卵孢子萌发对单卵孢株生物学性状的影响

 本文对经KMnO₄、H₂O₂刺激掘氏疫霉(Phytophthora drechsleri)卵孢子萌发建立的单卵孢株群体应用于掘氏疫霉遗传研究的可行性做了研究。2个掘氏疫霉菌株(A₁、A₂交配型各1株)经聚碳膜间隔配对产生的卵孢子用KMnO₄、H₂O₂以及不用上述氧化剂处理分别建立K、H、C 3个单卵孢株群体(卵孢子萌发率8-16%)。在群体水平上对来自同一亲本的上述3个群体生物学性状比较结果表明,H₂O₂处理刺激卵孢子萌发不影响生长速度、菌落形态、耐35℃高温生长、致病力及交配型的遗传稳定性,所建立的单卵孢株群体可用于上述性状的遗传研究;KMnO₄处理导致掘氏疫霉A₁和A₂交配型在自交后代各自分离为A₁、A₂、A₁A₂和A₂、A₁A₂,但不影响其他生物学性状的遗传稳定性,所建立的单卵孢株群体可用于除交配型性状以外的其他生物学性状的遗传研究,不宜用于交配型正常遗传规律的研究。用KMnO₄处理掘氏疫霉A₁或A₂交配型菌株单株自交产生的卵孢子,从A₁菌株自交后代获得A₂和A₁A₂以及从A₂菌株自交后代获得A₁A₂交配型单卵孢株的结果说明,掘氏疫霉异宗配合菌株体内可能同时包含控制A₁和A₂交配型的遗传因子,在正常条件下有1种交配型遗传因子不表达。KMnO₄处理可望作为揭示交配型遗传本质的有用试验手段。

EFFECTS OF OOSFORE TREATMENTS WITH KMnO4 OR H2O2 ON BIOLOGICAL CHARACTERS OF SINGLE-OOSFORE CULTURES OF FHYTOPHTHORA DRECHSLERI

The practicality of using single-oospore cultures from oospores treated with KMnO₄ or H₂O₂ for genetical researches of Phytophthora drechsleriwere studied.Two wild type isolates(an A₁ and another A₂ mating type) werw induced to self by membrane technique.Oospores treated with 0.1%KMnO₄ for 20 min.,0.3% H₂O₂ for 2 min.and without treated with those two oxidizers respectively germinated on S+L medium(with germination rates 8-16%),three single-oospores culture populations(each with 30 sin-gle-oospore cultures) were established and designated as K,H,C popula-tions from each parental isolate.Kesults from the comparison of biological characters among three S₁ populations showed that,the inheritance of grow-thrates,morphology of colong and sing leoospore cultures,gronth at 35℃,pathogenicity and mating type between H and C populations were similar,without side effect presented by treating oospores with H₂O₂It demonstrated that single-oospore cultures from oospores treated with H₂O₂could be used in genetical researches of those biological characters of P.drechsleri.The treatment of oospores with KMnO₁ resulted in variation of mating type in S₁ progeny,A₁ and A₂ seperated into A₁,A₁A₂,A₂ and A₂,A₁A₂ respectively,but the inheritance of other biological charaters were unaffected,demonstrated that K population could be used in the genetical researches of those biological characters except mating type.The variation of mating type in S₁ progeny resulting from oospores treated with KMnO₄ showed that,the genes controlling A₁ and A₂ mating type may be contained simultaneously in one heterothallic isolate of P.drechsleri and only one mating type expressed in normal condition.KMnO₄ treatment might be an effective method for revealing the genetical background of mating type of Phytophthora.