几种化学药剂对‘NJ72’油桃休眠解除的影响

Effects of Several Chemicals on Dormancy- releasing of 'NJ72' Nectarine

在进行果树温室栽培时 ,经常遇到萌芽率低、萌芽开花延迟、花器官发育差、座果率低的问题。本试验以‘NJ72’油桃为试材 ,观察了 3种药剂对解除芽休眠的影响。结果表明 ,2 % (NH2 ) 2 CS能提早花期 ,但存在药害现象。 6%KNO3不能提早花期 ,并且花期不整齐 ,5 %NH4NO3效果与 6%KNO3类似。同时化学药剂处理促进花芽内H2 O2 的积累 ,抑制了过氧化氢酶 (CAT)活性但促进了过氧化物酶 (POD)活性 ,超氧物岐化酶 (SOD)活性变化较小。化学药剂处理使花芽的呼吸速率增加 ,其中磷酸戊糖途径 (PPP)代谢增加 ,糖酵解 (EMP)降低 ,而三羧酸循环 (TCA)代谢波动较小。葡萄糖_6_磷酸脱氢酶 (G6PDH)

Poor, delayed and ununiform bud break is a major problem for peaches in greenhouse. To clarify the mechanism of breaking bud dormancy in nectarine, the effect of three dormancy_breaking agents, which were applied to the surface of dormant buds in two_year old 'NJ72' nectarine ( Prunus persica L. Batsch), was investigated. Treatment of intact nectarine plant with 2% thiourea(w/v) in November advanced flower bud break in the following spring by 20 days, while potassium nitrate was of no effect. But thiourea had a phytotoxic effect. The effect of ammonium nitrate was very similar to that of potassium nitrate, and flowering with the 2 nitrates was ununiform. In flower buds those were treated with dormancy_breaking agents, catalase activity was inhibited soon after treatment, whereas peroxidase activity increased, and changes of superoxide dismutase remained little. The rate of respiration in flower buds increased by chemicals during dormancy, among of which, the rate of the pentose phosphate pathway was also increased, while the rate of the Embden_Meyerh pathway decreased and the rate of tricarboxlic acid cycle changed little. The activity of glucose 6_phosphate dehydrogenase, the key enzyme in the pentose phosphate pathway(PPP), increased by dormancy_breaking agents, concomitantly with the activation of the pentose phosphate pathway.