不同苹果砧木对缺锌胁迫的耐性评价

为筛选适应缺锌胁迫环境的砧木资源，以山定子、丽江山定子、小金海棠、锡金海棠、新疆野苹果、八棱海棠、平邑甜茶、火焰海棠8种苹果砧木资源为试材，对砧木株高、干物质量、根系构型及锌含量等指标进行测定，利用模糊隶属函数法进行耐缺锌能力综合评价.结果表明： 缺锌处理下，丽江山定子、锡金海棠和新疆野苹果均先表现出新生叶小、簇生等缺锌症状，而小金海棠、火焰海棠缺锌症状不明显；缺锌显著降低了苹果砧木株高和地上部锌积累量，而小金海棠的降低幅度最小；缺锌胁迫下小金海棠和山定子叶片锌含量较高，分别为23.2和21.3 mg·kg^-1.采用模糊隶属函数法综合评价参试砧木耐缺锌能力：小金海棠最强，火焰海棠次之，山定子、锡金海棠、八棱海棠和平邑甜茶的耐缺锌能力较弱，丽江山定子和新疆野苹果的耐缺锌能力最弱.

Evaluation of zinc deficiency tolerance in different kinds of apple rootstocks.

The objective of this study was to screen and evaluate the zinc deficiency tolerance among eight apple rootstocks, i.e., Malus baccata, M. rockii, M. xiaojinensis, M. sikkimensis, M. sieversii, M. robusta, M. hupehensis and Malus ‘Flame’. The experiment took these 8 kinds of rootstocks as the research materials to observe and analyze the index of the rootstock’〖KG-*4〗s height, dry biomass, root architecture and zinc concentration, and with help of the fuzzy membership function to work out a comprehensive evaluation on their zinc deficiency tolerance. The result showed that several obvious zinc deficiency symptoms were observed in three kinds of rootstocks (M. rockii, M. sikkimensis and M. sieversii), such as dwarfed plant and newborn small leaves, while such symptoms were not obvious in M. xiaojinensis and M. ‘Flame’. The plant biomass, height and zinc accumulation of aerial part greatly decreased under zinc deficiency stress, while smaller reduction was observed in M. xiaojinensis than in other rootstocks. M. xiaojinensis and M. baccata had higher zinc concentrations in leaves than others. According to the fuzzy membership function and cluster analysis, the resistance of the eight apple rootstocks to zinc deficiency was ranked: M. xiaojinensis was the highest one; M. ‘Flame’ was the second; M. baccata, M. sikkimensis, M. robusta and M. hupehensis were rather weaker; M. rockii and M. sieversii demonstrated the highest sensitivity to zinc deficiency.