花蕾期高温对大棚与露地‘早生新水’梨花粉活力的影响

Effects of high temperature before blossom on pollen viability of ‘Zaoshengxinshui' pear cultured in greenhouse and field

以大棚、露地‘早生新水’梨露白期花枝为材料,分别在25℃、35℃处理2 h、4 h和6 h,以及40℃处理1 h、2 h和3 h,模拟高温对梨花粉活力的影响。结果表明:大棚‘早生新水’梨露白期花蕾耐高温低于35℃,尽管花粉量较多,但花粉萌发率低,花粉有效数量低;露地‘早生新水’梨露白期花蕾也不耐35℃高温。35℃高温持续时间越长,花粉萌发率越低,40℃高温显著降低花粉萌发率。35℃高温处理后,露地‘早生新水’梨花粉活力较大棚梨的修复能力强,但不耐受40℃长时间高温。高温对花粉管长度影响小。可见,温度对花粉萌发率影响大,对花粉活力起关键作用,大棚栽培应避免35℃以上的高温长时间出现。

The flowering branches before blossom of ‘Zaoshengxinshui’ pear cultured in greenhouse andfield were treated at 25 ℃ or 35 ℃ for 2 h,4 h,6 h or 40 ℃ for 1 h,2 h,3 h,and the effects of simulated hightemperature on the pollen viability of pear were studied. The results showed that the high temperature tolerance ofpear before blossom cultured in greenhouse was lower than 35 ℃. Although the pollen quantity was high,but thepollen germination rate was low,and the effective quantity of pollen was low. The high temperature tolerance ofpear before blossom cultured in field was lower than 35 ℃ also. The longer the duration of high temperature at35 ℃,the lower the pollen germination rate. The pollen germination rate reduced significantly at 40 ℃ hightemperature. The repair ability of pollen viability of ‘Zaoshengxinshui’ pear in field was stronger than that ofpear in greenhouse at 35 ℃, but it was not tolerant to high temperature at 40 ℃ for a long time. Hightemperature had little effect on the length of pollen tube. So, temperature had a great influence on pollengermination rate,and played a key role in pollen viability. A long time of high temperature above 35 ℃ ingreenhouse should to be avoided.