谷子根系水浸提液的化感自毒效应研究

Study on the auto-toxicity of water extracts of foxtail millet root

[目的]谷子重茬对下茬谷子出苗及生长影响较大,连作障碍较明显。[方法]本研究以谷子根系为试验材料,采用水浸液法,设置原液、稀释10倍液、稀释50倍液和稀释100倍液共4个浓度,以清水为对照,研究了不同浓度谷子根系水浸提液对其萌发种子根、芽和幼苗生长的影响。[结果]不同浓度谷子根系水浸提液对谷子萌发种子根、芽、及其幼苗生长发育影响表现为:高浓度(原液)抑制,低浓度(稀释10倍液、稀释50倍液、稀释100倍液)促进。原液处理下的萌发种子根长、芽长,株高、叶面积等农艺性状均受到了显著的化感抑制作用(P<0.05),其它处理下的根、芽及幼苗的生长均表现为化感促进作用,其中稀释50倍液处理对谷子的化感促进作用尤为显著(P<0.05)。幼苗SOD、POD、CAT活性随着浓度的增加均表现出先增加后降低的趋势。有效提高幼苗活性氧清除系统中抗氧化酶的活性,减轻对细胞的伤害。[结论]谷子根系中存在自毒物质,且会对其种子萌发和幼苗生长产生影响。谷子表现较强的自毒作用为进一步研究谷子连作障碍机理提供理论参考。

[Objectives] The continuous cropping of foxtail millet has big negative impact on the emergence and growth of next generation of crops. The objectives of present study were to determine the auto-toxicity effect of metabolites of foxtail millet root system on the seedlings growth of same crops. [Methods] Air dried foxtail millet roots were grinded and extracted with ultrasonic machine in distill water. Four concentrations of original, 10 times, 50 times, and 100 times diluted solution were selected. The effects of extract at different concentrations on root system, bud growth rate, and seedling growth rate were determined. [Results] The results showed that the effects of foxtail millet root water extracts on root and bud growth of germinated seeds and seedling growth were as follows. High concentration(Undiluted) could inhibit it’s growth, whereas low concentration(10 fold, 50 fold, and 100 fold dilution)could promote it. The original extract solution significantly inhibited the root length, bud length, plant height, and leaf area of seedlings, whereas stimulated function was detected for all lower concentrations, especially for the treatment of 50 times dilutions. The SOD, POD, and CAT activities of treated seedlings was increased firstly and then decreased with the increase of the extract concentration, which effectively improved the activity of antioxidant enzymes and protected plant cells from oxidative damage. [Conclusion] Foxtail millet root system possesses some auto-toxic substances which could impact seed germination and seedling growth of same crops. Present study could provide theoretical reference for further research on the mechanism of monocropping obstacle.