晚疫病菌有性與無性繁殖之遣傳

Inheritance of Sexual and Asexual Reproduction in Phytophthora infestans

張東柱(Tun-Tschu Chang) ； 柯文雄(Wen-Hsiung Ko)

《林業試驗所研究報告季刊》 6卷1期 (1991/03) Pp. 65-80

https://doi.org/10.7075/BTFRI.199103.0065

摘要

經分析Phytophthora infestans兩種同功酶（peptidase簡稱PEP和glucose phosphate isomerase簡稱CPI-l）之結果顯示，分離自同體基因菌株的自交系卵孢子菌株在PEP和CPI-1基因座均與個別的母株相同。然而分離自異體基因菌株的自交系卵孢子菌株在PEP和GPI-1基因分離l:2:1。此結果顯示P. infestans在無性繁殖體是雙核期。在533×550交配中，239個卵孢子菌株有283在GPI-1是雜交型異體基因且在PEP分離1:1；只有一分離株來自533的自交。菌株930（533×550的F1）在GPI-1和PEP是異體基因，其自交系卵孢子菌株分別在PEP和GPI-1分離1:2:1；當兩基因一起分析時，分離1:1:2:2:4:2:2:1:1。此結果顯示PEP和GPI-1並不連鎖在同一條染色體上。在926×936, 926×550，和932×550交配中，雜交和自交的比率分別為60:20, 75:0和74:1。15個單卵孢子菌株來自926或936的自交當926與936交配時用於配對實驗以進一步決定自交與雜交的比率。在10個配對中有7個配對的子代均來自雜交；其餘三個配對的子代來自雜交與自交。
自11菌株所得之自交卵孢子菌株含有A^1和A^2配對型，其中有8菌株含有A^1A^2的自交卵孢子菌株，然而分離株948(A^2)只含有A^2的自交卵孢子菌株。A^1、A^2和A^1A^2配對型均出現在7個交配組合的卵孢子菌株。自兩P. infestans菌株所得游走子菌株的菌絲直線生長均很一致，然而其卵孢子菌株則有很大的變異；菌落形態也有相似的趨勢。此結果假設異體多對基因可能決定菌絲生長和菌落形態，同時也支持Phytophthora在無性繁殖體期是雙核體的假說。

關鍵字

晚疫病菌 ； 遺傳

並列摘要

The results from analysts of isozyme patterns of P. infestans show that selfed oospore culturcs obtained from isolates heterozygous at peptidase (PEP) and glucose phosphate isomerase (OPT-1) loci segregatad 1:2:1, and that all seled oospore cultures obtained from homozygous isolates were identical with their respective parents. These results indicate that P. infestans is diploid in vegetative state. In the pairing 533×550, 238 of 239 single-oospore cultures were heterozygous hybrid at GPI-1 laces and segregated 1:1 at PEP locus. One of the 239 cultures was from selfing of 533. Single-oospore cultures from selfing of isolate 930 (F1 of 533×550) heterozygous at PEP and GPI-1 loci segregated 1:2:1 at each locus and segregated 1:1:2:2:4:2:2:1:1 when two loci were analyzed together, indicating slice PEP and GPI-1 genes are not linked. In the pairings 933×926, 926×550 and 932×550, the ratios of hybrids: selfs were 60:20, 75:0 and 74:1, respectively. Fifteen single-oospore cultures from selling of either 936 or 926 from the pairing 936×926 were paired to determine the ratios of self: hybrid. Seven of 10 pairings produced only hybrid offspring. The other three pairings produced hybrid and self.
Beth A1 and A2 mating types were present in the selfed progenies of 11 isolates tested. Eight of these isolates also produced A1A2 type. The selfed progeny of the A2 isolate 948 consisted of only A2 type. A1, A2 and A1A2 types were present in the progenies from all the seven crosses tested. Rate of linear extension of mycelia of zoospore progenies of two tested isolates of P.infestans was relatively uniform. However, there was a great variation in growth rate in progenies of selfed oospores. The character of colony pattern also showed variation in oospore progenies but not zoospore progenies. Results of the study suggest that heterozygous polygenes were involved its determining growth rate and colony morphology of these fungi and support the hypothesis that species of Phytophthora are diploid during the vegetative phase.

並列關鍵字

Phytophthora infestans ； genetics