印度梨形孢和CaCl_(2)对香蕉抗寒性的影响

Effects of Piriformospora indica and CaCl_(2) treatments on cold resistance of banana

以‘天宝蕉’为材料,研究印度梨形孢和CaCl_(2)处理对香蕉抗寒性的影响.将香蕉苗分别进行2 g·L^(-1) CaCl_(2)喷施叶片(T1)、印度梨形孢根系定殖(T2)、T1+T2复合(T3)处理,以未作处理的香蕉苗为对照(CK),比较4组香蕉苗在28和4℃处理12 h后的表型及叶片的相对电解质渗透率、可溶性糖含量、过氧化氢(H_(2)O_(2))浓度、丙二醛(MDA)浓度的差异.结果表明:28℃下,3种处理对香蕉表型均无明显影响,但均可以降低叶片电解质渗透率,提高叶片的可溶性糖含量、H_(2)O_(2)浓度、MDA浓度;4℃处理后,3个处理组香蕉苗的冷害症状均轻于CK组.4℃下,T1组叶片的电解质渗透率低于CK组(P>0.05,相比对照组下降19.9%),T2和T3组的电解质渗透率显著低于CK组(P<0.05,相比对照组,分别下降47.8%和52.6%);T1、T2和T3组的可溶性糖含量和H_(2)O_(2)浓度均显著低于CK组(P<0.05),MDA浓度也均低于CK组.结果显示,根系定殖印度梨形孢和叶片喷施CaCl_(2)处理均能提高香蕉苗的抗寒性,二者复合处理的效果最佳.

To investigate the effects of Piriformospora indica and CaCl_(2) treatments on the cold resistance of banana, ‘Tianbaojiao’ seedlings were treated with 2 g·L^(-1) CaCl_(2) spraying(T1), P.indica root colonization(T2) and the combination of both(T3) at 28 and 4 ℃ for 12 h. Changes in seedling phenotypes were monitored and relative electrolyte leakage value, contents of malonaldehyde(MDA), soluble sugar and H_(2)O_(2) before and after low-temperature treatment were determined. The results showed that none of the 3 treatments exerted significant influence on the phenotype of banana seedlings at 28 ℃, but led to lower electrolyte leakage values and higher foliar soluble sugar, H_(2)O_(2) and MDA contents. After low-temperature treatment, cold injury symptoms in all the treatment groups were milder than the control that did not receive P.indica root colonization nor CaCl_(2) spraying, resulting in 19.9%, 47.8% and 52.6% reductions in foliar electrolyte leakage values in T1(P>0.05), T2(P<0.05) and T3(P<0.05), respectively. Soluble sugar and H_(2)O_(2) contents in the leaves of T1, T2 and T3 were all significantly declined than the control(P<0.05). Foliar MDA contents were also numerically lower in T1, T2 and T3. To summarize, both P.indica root colonization and CaCl_(2) spraying can enhance the cold resistance of banana, and the combined application of both showed the optimum accelerative effect.