水分胁迫条件下10种苹果砧木抗旱性评价

Evaluation of Drought Resistance of Ten Apple Rootstocks

在盆栽条件下对10种苹果砧木进行了水分胁迫下的抗性鉴定,对旱害指数和相对生长量进行了聚类分析,结果表明,新培育的砧木品系Luo-6、Luo-2是抗旱性强的砧木,在土壤相对含水量40%～45%的中度水分胁迫下,新梢相对生长量分别可以达到92.13%和88.56%,其中,Luo-6在30%～35%的重度水分胁迫下24d才出现1级旱害症状,新梢相对生长量可达78.40%,Luo-2能忍受10d以下短时间的重度水分胁迫;莱芜茶果、黄海棠、海棠果、莱芜难咽、八棱海棠是中等耐旱,可以忍受20d以上的中度干旱,新梢相对生长量保持在66.13%～88.56%;平邑甜茶、六蜜海棠、山定子对水分胁迫非常敏感,在相对含水量55%～60%的轻度水分胁迫下17～31d即出现1级旱害症状,新梢相对生长量下降到70%以下。

Drought resistance of 10 species or clones of apple rootstocks was assessed under potted cultural conditions. Cluster analysis of drought injury index and relative growth was employed to detect the resistance of the rootstocks to water stress. Results showed that the newly-bred clones of Luo-6 and Luo-2 held high resistance to drought stress, their shoot relative growth(RG)sustained 92.13% and 88.15% respectively under moderate water stress with a soil relative water content (RWC) of 40%～45%. Even after 24 days' severe water stress, Luo-6 appeared slight drought-injury symptom with a RG of 78.40%. But Luo-2 could only tolerate 10 days' severe water stress. Laiwuchaguo (Malus pruniforlia Borkh.), Huanghaitang (M. robusta Rehd.), Haitangguo (M. pruniforlia Borkh.), Balenghaitang (M. robusta Rehd.) and Laiwunanyan (M. micromalus Makino) were moderately tolerant. They could tolerate moderate water stress for more than 20 days with RG ranging from 66.13% to 88.56%. Pingyitiancha (M. hupehensis Rehd.), Liumihaitang (M. micromalus Makino.) and Shandingzi (M. baccata Borkh.) were sensitive to water stress, they appeared drought-injury symptom with a low RG of less than 70% even after 17～31days' slight water stress with a RWC of 55%～60%.