果实膨大期干旱胁迫对‘红富士’苹果树生理特性的影响

Effect of Drought Stress on Physiological Characteristics of‘Red Fuji’ Apple Trees during Fruit Expansion Period

利用热扩散技术和光合仪,以正常灌溉(CK)为对照,设干旱胁迫(C1)和半根区灌溉(C2)2个处理,对果实膨大期阿克苏‘红富士’苹果树生理特性(茎流、光合)在不同水分处理下的响应进行分析。结果表明:果树蒸腾耗水集中在白天,在傍晚灌溉可降低水分对果树蒸腾作用的影响。水分过多可能抑制果树蒸腾作用,灌溉当天CK日茎流量值下降。短时间干旱能提升‘红富士’苹果树叶片的水分利用效率。干旱胁迫条件下,‘红富士’苹果树单日茎流速率为“窄型”曲线,茎流开始时间较晚,结束时间较早;随着干旱时长的增加茎流速率谷值推迟,根系吸水活动减弱但时间延长;果树干旱胁迫时蒸腾耗水受天气影响小。果实膨大期‘红富士’苹果耐干旱时长约为50 d,此时光合作用非气孔因子占主导,50 cm深土壤体积含水率对‘红富士’苹果树适时灌水有一定的指示作用。缺水条件下,茎流速率与蒸腾速率、净光合速率和气孔导度呈显著正相关,可见,不能一味地减少水分,灌溉方式可采用“少量多次”,选择傍晚或者早上灌溉。

In order to provide technology support for improving water use efficiency of fruit trees in arid areas,with normal irrigation(CK)as control,heat diffusion technology and photosynthetic apparatus was used and two treatments of drought stress were set to analyze the response of physiological properties(stem flow,photosynthesis)to Akesu‘red Fuji’apple trees under different water treatments during fruit expansion period(C1)and semi-root area irrigation(C2).The results showed that the transpiration water consumption of fruit trees happened in the daytime,and irrigation in the evening could reduce the influence of water on the transpiration of fruit trees.Excessive water content may inhibit transpiration of fruit trees,and the daily stem flow value of CK dropped on the day irrigation.Short-term drought could improve water use efficiency of‘red Fuji’apple tree leaves.Under drought stress,the stem flow rate of‘red Fuji’apple tree in a single day was a“narrow”curve,the stem flow began later and ended earlier.With the increase of drought duration,the valley value of stem flow rate was delayed,and the root water absorption activity was weakened,but the time was prolonged.The transpiration water consumption of fruit trees under drought stress was less affected by the weather.The drought tolerance duration of‘red Fuji’apple was about 50 d during the fruit expansion period,and the photosynthesis stomatal factor was dominant and non-stomatal factor was dominant.The volume moisture content of 50 cm deep soil had a certain indication effect on the timely irrigation of‘red Fuji’apple trees.Under the condition of water shortage,the stem flow rate had significantly positive correlation with T r,P n and G s.Therefore,the water content cannot be reduced blindly,and the irrigation method can be adopted for a small number of times,the evening or morning irrigation should be chosen.