砧用瓠瓜抗枯萎病相关性及杂种优势分析

枯萎病是一种严重危害瓜类蔬菜生产的土传病害,嫁接栽培是防治瓜类枯萎病的有效方法。该文研究了砧用瓠瓜种质幼苗生长指标与抗病性的相关性,并对抗病杂种优势进行了分析。结果表明:(1)砧用瓠瓜种质H041对西瓜枯萎病表现高抗(HR),对瓠瓜枯萎病表现抗病(R),种质H01、H05和杂交组合H01×H041、H041×H05、H05×H041对两种枯萎病均表现抗病(R)。(2)砧用瓠瓜幼苗接种西瓜枯萎病菌后,病情指数与下胚轴粗度呈显著负相关;接种瓠瓜枯萎病菌后,总根长、根系表面积与病情指数呈极显著负相关,表明砧用瓠瓜对枯萎病的抗病性与根系生长具有相关性,可以根据根系生长情况快速评价砧用瓠瓜对瓠瓜枯萎病的抗性表现。(3)分析砧用瓠瓜杂交组合的抗病性杂种优势显示,供试杂交组合H05×H041对西瓜枯萎病具备超中亲优势;杂交组合H01×H041和H02×H041对瓠瓜枯萎病抗性具有负向杂种优势。综合研究结果发现,种质H01、H041、H05兼抗西瓜枯萎病和瓠瓜枯萎病,且配制出的杂交组合表现抗性杂种优势,可作为选育抗两种枯萎病的砧木或栽培品种的抗源亲本,其中H041可作为优势骨干亲本。

Fusarium wilt resistance correlation and heterosis in rootstock-used gourd

Fusarium wilt is a devastating soil-borne disease which had limited the production of gourd vegetables. Grafting cultivation is an effective method to control F. wilt. In order to obtain rootstock-used gourd germplasm with strong disease resistance and to select hybrid combinations, the correlation between seedling growth index and disease resistance was discovered, and the heterosis of disease resistance was analyzed. The results were as follows:(1)Rootstock-used gourd germplasm H041 showed high resistance(HR)to watermelon F. wilt and resistance(R)to clavated calabash F. wilt, respectively. And two rootstock-used gourd germplasm(H01 and H05)and three hybrid combinations(H01×H041, H041×H05 and H05×H041)showed resistance(R)to these two kinds of F. wilt.(2)The di-sease index of rootstock-used gourd seedlings was significantly negatively correlated with hypocotyl coarseness after treating with watermelon F. wilt. And the root length and root surface area of the seedlings had significantly negative correlation with disease index after treating with clavated calabash F. wilt. This indicates that the resistance of the disease is correlated with root growth. The resistance of the disease can be evaluated rapidly according to root growth.(3)Furthermore, the disease-resistance hybrid heterosis of rootstock-used gourd germplasm showed that, hybrid combination H05×H041 showed negative mid-parent heterosis to watermelon F. wilt. H01×H041, H02×H041, H041×H01 and H05×H041 showed negative heterosis for resistance to clavated calabash F. wilt. In conclusion, rootstock-used gourd germplasm H01, H041 and H05 showed resistance against two kinds of F. wilt, and there was resistance heterosis on the hybrid combinations of these germplasms. Hence, H01, H041 and H05 could be used as rootstock or elite parents for resistance breeding against two kinds of F. wilt, and H041 could be used as the backbone parent.