3个桃品种对淹水胁迫的生理响应及耐涝性评价

Responses and Tolerance of Three Peach Cultivars to Waterlogging

【目的】研究浙江省主栽3个不同成熟期桃品种响应淹水胁迫的形态及生理特性变化,综合评估其耐涝性,为桃抗涝栽培技术制定及耐涝品种的选育提供参考。【方法】以早熟春红、中熟新川中岛和晚熟锦绣等3个桃品种的毛桃砧1年生嫁接苗为材料,通过盆栽模拟涝害试验,比较植株表型、根系细胞解剖结构、涝害指数变化,同时测定叶片光合特性、渗透调节物质含量及抗氧化酶活性等生理生化指标变化,并利用隶属函数及主成分分析评价耐涝性。【结果】淹水使砧木根系受损腐烂,皮层细胞裂解形成气腔;叶片萎蔫黄化脱落,涝害指数持续上升,其中春红品种的涝害指数始终显著低于新川中岛、锦绣品种;随着淹水进程,叶片光合作用受阻,净光合速率(P_(n))、蒸腾速率(T_(r))、气孔导度(G_(s))等光合参数持续下降,胞间CO_(2)浓度(C_(i))逐步上升,春红的光合性能始终强于新川中岛和锦绣;叶片细胞膜透性不断增加,丙二醛(MDA)和可溶性糖(SS)含量、超氧化物歧化酶(SOD)和过氧化物酶(POD)等酶活性总体呈现先上升后下降趋势;应用隶属函数和主成分分析3个桃品种耐涝性强弱依次为:春红>新川中岛>锦绣。【结论】持续淹水导致桃根系及叶片光合性能严重受损,3个不同成熟期桃品种的耐涝性存在显著差异,其中春红耐涝性表现最好。

【Objective】Morphological and physiological changes and waterlogging tolerance of three major peach cultivars in Zhejiang Province in response to flooding stress were studied.【Method】One-year-old seedlings of early(Chunhong),mid(Shinkawa Nakajima),and late(Jinxiu)varieties of peaches grafted on Maotao rootstocks planted in pots were treated with or without simulated waterlogging.Phenotype,waterlogging index,and root cell anatomical structure of the plants were compared,and photosynthetic parameters,osmotic adjustment substances content,and antioxidant enzyme activities determined.Waterlogging tolerance of the cultivars was evaluated using the membership function and principal component analyses.【Result】Prolonged waterlogging progressively damaged the tips of the peach plant roots showing lysed cortical cells with irregular air cavities,and the roots eventually rotted.As the waterlogging index continued rising the leaves also wilted,yellowed,and even shed.The index on Chunhong was significantly lower than those of Shinkawa Nakajima and Jinxiu.The leaf photosynthetic capacity was hindered by the waterlogging with significantly declined net photosynthetic rate(P_(n)),transpiration rate(T_(r)),and stomatal conductance(G_(s)),and raised intercellular CO_(2)concentration(C_(i)).The Chunhong variety maintained a higher photosynthetic capacity than did either Shinkawa Nakajima or Jinxiu.Meanwhile,under the stress,the leaf cell membrane permeability continued to rise,while the contents of MDA and SS and the activities of SOD and POD increased initially and then decreased.The membership function and principal component analyses ranked the waterlogging tolerance of these cultivars as Chunhong>Shinkawa Nakajima>Jinxiu.【Conclusion】Prolonged waterlogging could cause severe damages to the roots and photosynthetic function of the peach plants.The degree of tolerance to such stress varied significantly among the 3 cultivars,and Chunhong was seen most tolerant to waterlogging as shown in the pot experiment.