担孢子介导传播对香菇双分体病毒LePV1群体形成的影响

Effect of virus-transmission via basidiospore on the population of lentinula edodes partitivirus 1

摘要:

【背景】LePV1为中国香菇种质资源中携带的主要病毒之一。在前期研究中，根据分子序列特征将LePV1带毒菌株群体分为两个分子类群(亚型I和亚型II)，亚型I包含大部分带毒香菇菌株，而亚型II仅包含少数几个供试带毒香菇菌株，在地理上相距遥远的不同遗传背景香菇菌株中发现了同一LePV1分子类型。【目的】探究担孢子介导传播对香菇双分体病毒LePV1群体形成的影响。【方法】比较不同亚型菌株的有性担孢子后代带毒率差异，并采用单单杂交和单双杂交方式分析杂交对LePV1群体形成的影响等。【结果】亚型I中栽培菌株ZP51和野生菌株YS94的担孢子带毒率分别为70%和100%，亚型II中栽培菌株ZP28和野生菌株YS5的担孢子带毒率分别为45%和55%，暗示亚型I菌株担孢子传毒效率高于亚型II；当杂交配对的任一亲本携带LePV1时，无论是单单杂交还是单双杂交，获得的杂交子带毒率为100%。【结论】不同亚型担孢子病毒携带率的不同和杂交在香菇双分体病毒LePV1群体形成中可能发挥着重要作用；此外，LePV1不能在杂交不亲和的单核体之间传播，也不能在不亲和的单双杂交配对中进行传播；在杂交可亲和的单双杂交配对中，杂交成功的杂交子在与亲本双核体菌丝接触一段时间后，可以将病毒LePV1通过胞质传播传给亲本双核体菌丝体。该研究为明确香菇双分体病毒LePV1传播规律及LePV1群体形成机制提供了线索。

Abstract:

[Background] Lentinula edodes partitivirus 1 (LePV1) is a major mycovirus identified in L. edodes germplasm. Previous to this study, LePV1 isolates from the Chinese genetically-diverse L. edodes core collection were grouped into two distinct clades (subtype I and subtype II), with the majority in subtype I; The same LePV1 molecular isolate was found in L. edodes strains that were genetic-diverse and geographically far away. [Objective] To identify the effect of virus-transmission via basidiospore on the population of Lentinula edodes partitivirus 1. [Methods] We compared the virus-carrying rate of basidiospores between subtype I and subtype II, and analyzed the effect of hybridization (Mon-Mon and Di-Mon) on the population of LePV1. [Results] The virus-carrying rates of basidiospores was 70% in ZP51 and 100% in YS94 in subtype I, while it was 45% in ZP28 and 55% in YS5 in subtype II. Virus-transmission efficiency of basidiospore from strains in subtype I was higher than that of basidiospores from strains in subtype II. If one of the parental basidiospores carries LePV1, the obtained hybrid will carry LePV1 either in Mon-Mon crossing test or Di-Mon crossing test. [Conclusion] The different virus-transmission efficiency of basidiospore from strains in different subtypes, and plasmogamy duringhy bridization maybe play an important role in the formation of the population of LePV1. In addition, LePV1 was not spread from spores that carried virus to its incompatible monokaryons or dikaryons in Mon-Mon crossing test or Di-Mon crossing test. Additionally, the obtained hybrids could transmit LePV1 to the paring heterokaryons in the successful Di-Mon crossing test. This research presented here firstly provide experimental evidence and clues for us understanding the transmission characteristics and population formation of LePV1.