怀集药用野生稻农艺性状及其抗氧化酶特性分析

【目的】明确自然条件下不同生长期怀集药用野生稻与栽培稻中花11的农艺性状及叶茎根中抗氧化酶活性差异，为进一步挖掘药用野生稻的有利抗性基因及培育抗性水稻新品种提供理论依据。【方法】选取饱满的怀集药用野生稻和栽培稻中花11种子进行常规催芽及营养液种植培养，培养至3叶期时进行移栽定植，测定农艺性状指标；继续用木村B营养液在自然光照条件下进行培养，分别于移栽后第30 d和抽穗期后第10 d对叶茎根取样，测定叶茎根中的抗氧化酶［超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT）］活性。【结果】怀集药用野生稻的发芽率（45.83%）显著低于栽培稻中花11（97.65%）（P< 0.05，下同），且生长至3叶期的时间显著长于栽培稻中花11；怀集药用野生稻的株高和地上高显著高于栽培稻中花11，但其根长、地上重和根重显著低于栽培稻中花11。不同生长期怀集药用野生稻与栽培稻中花11的植株生长表型差异明显，表现为怀集药用野生稻叶面宽大、叶长较长、叶倾角大，植株分蘖数少、根系欠发达，植株穗数少、穗上着粒少、籽粒灌浆慢。在抗氧化酶活性方面，怀集药用野生稻叶片和茎的SOD活性显著低于栽培稻中花11，而根SOD活性在移栽后第30 d显著高于栽培稻中花11；叶片和茎的POD活性均在移栽后第30 d显著高于栽培稻中花11，抽穗后第10 d显著低于栽培稻中花11，根POD活性在2个不同生长期均显著低于栽培稻中花11；叶片CAT活性在移栽后第30 d显著高于栽培稻中花11，茎CAT活性在2个不同生长期均显著低于栽培稻中花11，根CAT活性则显著高于栽培稻中花11。【结论】怀集药用野生稻的种子存在深休眠性，萌发困难，其植株农艺性状及生长表型与栽培稻中花11差异显著，且在关键营养生长期具有较高的POD和CAT活性，即怀集药用野生稻具备高光效叶片生长特点及优良抗氧化特性，可作为今后有利抗性基因高效筛选和利用的优质野生稻种质资源。

Agronomic characters and antioxidant enzyme characteristics of Oryza officinalis Wall in Huaiji

【Objective】This study was conducted to clarify the differences of agronomic characters and activities of antioxidant enzymes in leaves, stems and roots between Oryza officinalis Wall in Huaiji and cultivated rice Zhonghua 11 at different growth stages under natural growth conditions, which would provide theoretical basis for further exploring the valuable resistance genes and breeding resistant rice varieties.【Method】The seeds of O.officinalis Wall in Huaiji and Zhonghua 11 were germinated and cultured in nutrient solution under natural condition.The seedlings were transplanted until three-leaf stage, and the growth morphological indexes were measured.The seedlings were continued to be cultured with Mucun B nutrient solution under natural light.The leaves, stems and roots were sampled to determine the activities of superoxide dismutase(SOD), peroxidase(POD) and catalase(CAT) at the day 30 after transplanting and the day 10 after heading.【Result】O.officinalis Wall in Huaiji showed significant lower seed germination percentage(45.83%) as compared with Zhonghua 11(97.65%) (P< 0.05, the same below), the time growing to three-leaf stage was also significantly longer than Zhonghua 11.The plant height and above-ground height of O.officinalis Wall in Huaiji were significantly higher than that of Zhonghua 11, but the root length, above-ground weight and root weight were significantly lower than that of Zhonghua 11.There were great differences in plant growth phenotype between O.officinalis Wall in Huaiji and Zhonghua 11 at different growth stages, as to the wider leaf, longer leaf length, larger leaf angle, less tiller number, underdeveloped root system, smaller number of panicles and grains and slow grain filling in O.officinalis Wall in Huaiji.In addition, SOD activities in leaves and stems of O.officinalis Wall in Huaiji were significantly lower than those in Zhonghua 11, and the root SOD activity of O.officinalis Wall in Huaiji was significantly higher than that of Zhonghua 11 at day 30 after transplanting.The POD activity of leaves and stems of O.officinalis Wall in Huaiji was higher than that of Zhonghua 11 at day 30 after transplanting, and lower than that of Zhonghua 11 at day 10 after heading, while the root POD activity was significantly lower than that of Zhonghua 11 at these two growth stages.The CAT activity of O.officinalis Wall in Huaiji leaves were significantly higher than Zhonghua 11 at day 30 after transplanting, but the CAT activity of stems was significantly lower than that of Zhonghua 11at day 30 after transplanting and at day 10 after heading respectively, while the root CAT activity was significantly higher than that of Zhonghua 11 at these two growth stages.【Conclusion】The study showed that deep dormancy and low germination percentage are found in the seed of O.officinalis Wall in Huaiji.Significant differences are found in agronomic characters and growth phenotype between O.officinalis Wall in Huaiji and Zhonghua 11, companied with higher enzyme activity of POD and CAT at the key vegetative growth stage as compared to Zhonghua 11.It is suggested that O.officinalis Wall in Huaiji has the growth characteristics of high light efficiency leaf and excellent antioxidant properties, which may be used as high quality wild rice germplasm resources to play a role in efficient screening and utilization of valuable resistance genes in the future.