灌水量对早实核桃枝叶生长及叶绿素荧光特性的影响

Effects of irrigation amount on the growth of shoots and leaves and chlorophyll fluorescence characteristics of precocious walnuts

为了探明灌水量对早实核桃光合面积和光合能力的影响,为科学灌溉提供理论依据,以2005年栽植的早实核桃‘绿岭’为试材,分别设0,15,30,45和60 kg/(株·次)5个灌水处理,以园片常规管理的灌水量600 kg/(株·次)为对照,研究了不同灌水处理早实核桃的枝叶生长状况及叶绿素荧光特性。结果表明,随着灌水量的增加,新梢生长量和叶面积指数都显著增大,两者均以对照最大,分别为17.25 cm和4.66,对照与45和60 kg/(株·次)2个灌水处理差异不显著;随着灌水量的减少,叶片的最大荧光(Fm)、PSⅡ最大光化学效率(Fv/Fm)和PSⅡ电子传递量子产量(ΦPSⅡ)均逐渐降低,初始荧光(Fo)则逐渐增大。土壤含水量低于田间持水量的60.27%时,PSⅡ反应中心电子传递受到抑制,最大光化学效率显著降低。

In order to provide a theoretical basis for scientific irrigation, we conducted this experiment to determine the effects of irrigation amount on photosynthetic area and capacity of precocious walnuts. Using ＇ Luling＇ walnut trees planted in the spring of 2005 as trial materials, the effects of irrigation amount on the growth of shoots and leaves and chlorophyll fluorescence characteristics of precocious walnuts were studied by 5 irrigation treatments i. e. 0, 15, 30, 45 and 60 kg water per plant every time respectively. The control was orchard conventional irrigation amount （600 kg per plant one time）. The results showed that with the increasing of irrigation amount, the shoot length and leaf area index increased significantly, and those of control were 17.25 cm and 4.66 respectively, which were the largest. There were no significant differences between control and irrigation treatments with 45 and 60 kg water per plant one time. With the decreasing of irrigation amount, the maximum fluorescence （ Fm ）, PS Ⅱ maximum photochemical efficiency （ Fv/Fm ） and PS Ⅱ electron transfer quantum yield （φPSⅡ） reduced gradually, the initial fluorescence （Fo） increased gradually. When the soil water content was lower than 60.27% of field capacity, PS Ⅱ reaction center electron transfer was inhibited, and the maximum photochemical efficiency was significantly reduced.