铁核桃根与叶水浸提液对果园间作绿肥植物的化感作用及其生理机制

以西南地区具有代表性的16种绿肥植物为受体材料,采用培养皿药膜法研究了铁核桃(Juglans sigillata)根水浸提液对受体种子发芽率及幼苗鲜重、干重的化感效应;并进一步研究了铁核桃根、叶水浸提液和胡桃醌对化感效应存在明显差异的4种绿肥植物(绿豆、红三叶、白三叶、花生)种子萌发与幼苗生长以及抗氧化酶特性的影响,以筛选适宜中国西南地区核桃园种植的绿肥植物,探讨核桃根和凋落物对绿肥作物的化感作用机制。结果表明:(1)铁核桃根水浸提液对绿豆的发芽率没有影响,但对绿豆幼苗鲜重和干重有显著抑制作用,而对其他15种绿肥的发芽率和鲜重、干重均有抑制作用。(2)胡桃醌显著抑制绿豆种子萌发,而铁核桃根或叶水浸提液对绿豆种子萌发没有影响。(3)铁核桃根或叶水浸提液以及胡桃醌对绿肥植物幼苗生长的化感效应趋势一致,但核桃根或叶水浸提液的化感效应强于胡桃醌。(4)绿豆幼苗在铁核桃根或叶水浸提液以及胡桃醌处理下,超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)的活性均高于其他3种(红三叶、白三叶、花生)受体幼苗,表明绿豆清除活性氧能力高,细胞受损害程度较低,受化感作用影响最弱。研究认为,绿豆为适宜中国西南地区幼龄核桃园种植的间作绿肥植物。

Allelopathic Comparison and Physiological Mechanism of Aqueous Extract from Juglans sigillata Dode Root and Leaf on Orchard Intercropping Green Manure Plants

In this study, we investigated the allelopathy mechanism of the aqueous extract of Juglans sigillata root on the seed germination and seedlings growth of sixteen kind of typical green manure seeds in the southwest region by method of Petri dish bioassay. In addition, we further studied the allelopathic effects of the J. sigillata leaf and root aqueous extracts and juglone on 4 kinds of green manure plants (mung bean, red clover, white clover, peanuts) on difference of seed germination and seedling growth and analysis of antioxidant enzyme properties. Our purposes are to screen suitable green manure plants grown in the walnut gardens of southwestern China, and investigate the allelopathic mechanism of walnut roots and litter on green manure crops. The results showed that: (1) the aqueous extract of J. sigillata root had no effect on the germination rate of mung bean, but the fresh and dry weight of mung bean seedlings were significantly inhibited, while the germination rate, fresh weight and dry weight of the other 15 kinds of green manure were inhibited; (2) the germination of mung bean seeds was inhibited significantly by juglone, but the aqueous extract of J. sigillata root or leaf had no effect on the germination of mung bean seeds; (3) allelopathic effects of the aqueous extract of J. sigillata root or leaf compare with juglone on the growth of green manure plants were consistent, but the allelopathic effect was stronger than that of walnut roots and leaves; (4) the activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) in the seedlings of mung bean under J. sigillata root or leaf and juglone were higher than those of the other 3 kinds of receptor seedlings, and the scavenging ability of reactive oxygen species was high, the degree of cell damage was low and affected by allelopathy. Studies indicated mung bean is an intercropping green manure plant suitable for young walnut gardens in Southwest China.