马铃薯体细胞杂种的青枯病抗性鉴定

Evaluation of Resistance to Rolstonia solanacearum of Potato Somatic Hybrids

本试验对马铃薯四倍体栽培种(Solanum tuberosum)的双单倍体系81-15与二倍体野生种S.cha-coense的原生质体融合株系进行了青枯病抗性鉴定,其目的是对利用体细胞融合技术获得抗青枯病种质的有效性及抗性鉴定技术进行评价,获得抗病育种材料。结果表明:在鉴定的18个体细胞融合株系中,抗性分离表现为从感病(S)到抗病(R),多数表现为中感(MS)到中抗(MR)水平。田间病圃鉴定、人工接种鉴定和分子标记鉴定的结果显示:田间病圃鉴定的病情指数(DI)和人工接种鉴定病级(DS)的相关性达到极显著水平(DI=-0.39+4 DS,r2=0.921),双侧翼SCAR标记SCA07446和SCA12980鉴定同时具有两个标记特异带的株系均为前两种鉴定表现为中感(MS)以上的材料。综合分析同时利用3种方法鉴定的结果:CHT-3、CHT-5、CHT-6、CHT-10、CHT-15等5个株系为抗病材料,证明体细胞融合是利用野生种质资源抗性的有效途径。

The evaluation of resistance to bacterial wilt of the somatic hybrids, which were derived from the protoplast fusion between dihaploid of Solarium tuberosum 81-15 and wild species S. chacoense, was conducted in addition to the investigation of their morphological and biological characteristics. The purposes were to assess the capability of the somatic fusion strategy in transferring bacterial wilt resistance between species, efficiency of the resistance evaluation techniques and potential use of the somatic hybrids in potato breeding programme. The results showed that resistance among 18 somatic hybrids tested varied from susceptible（S）to resistance（R）with majority assigned to mid-susceptible （MS）and mid-resistance（MR）. There was a significant linear relationship between the disease score（DS）, a criteria used in the artificial inoculation of the pathogen against the hybrids in plastic house, and the disease index（DI）, a criteria used in the field trial by growing hybrids in the infected soil, which could be represented as DI =-0.39＋4DS, （r^2=0.921）. The flank SCAR markers, SCA07446 and SCA12980, were applied for the resistance evaluation and the specific bands of the two markers present in the hybrids showed resistance levels from MS to R in the inoculation and field trial. By considering together the evaluation results, somatic hybrids CHT-3, CHT-5, CHT-6, CHT-10 and CHT-15 performed high resistance to bacterial wilt, indicating that somatic fusion is an efficient way to use the resistance of wild potato germlasms.