1,2,4-三氯苯胁迫对不同基因型水稻灌浆期生理特性及产量的影响

在盆栽土培条件下,研究了5种浓度(0、10、20、40、80 mg/kg土)的1,2,4-三氯苯(TCB)对两种基因型水稻品种宁粳1号(敏感基因型)和扬辐粳8号(耐性基因型)产量及灌浆期生理特性的影响。结果表明:TCB对两种基因型水稻产量和灌浆期生理特性的影响具有显著差异,随着TCB浓度的增加,宁粳1号的产量呈现递减趋势,而扬辐粳8号呈低浓度下产量增加高浓度下产量显著降低的趋势,在中高浓度TCB(40、80 mg/kg)处理时,宁粳1号每盆穗数,每穗粒数,结实率显著降低且降幅显著大于扬辐粳8号,两个基因型品种千粒重变化都不明显。宁粳1号株高、干物重受TCB抑制程度较明显,降幅显著大于扬辐粳8号。在低浓度TCB(20 mg/kg)处理时,宁粳1号根系活力、叶绿素含量、可溶性蛋白质含量显著降低,而扬辐粳8号有所提高。随着TCB浓度的增加,两个基因型品种叶片抗氧化酶SOD、POD、CAT活性均呈先升后降趋势,且在低浓度TCB(10 mg/kg、20mg/kg)处理时,扬辐粳8号抗氧化酶活性极显著高于宁粳1号,在高浓度TCB(80 mg/kg)TCB浓度胁迫下,宁粳1号抗氧化酶活性极显著低于对照,且降幅极显著大于扬辐粳8号,且MDA含量增幅较大,膜质过氧化程度高。总体而言,低浓度TCB对扬辐粳8号的产量和灌浆期株高、干物重、叶绿素含量、叶片蛋白质含量和抗氧化酶活性具有一定的促进作用,中高浓度TCB对宁粳1号的抑制作用显著大于扬辐粳8号,扬辐粳8号在不同浓度的TCB处理下较宁粳1号表现出较强的耐迫性和适应性。

Effects of 1, 2, 4-trichlorobenzene on physiological characteristics during grain filling stage and grain yield of rice of different genotypes

A soil culture experiment was conducted to study the effects of 1, 2, 4-trichlorobenzene (TCB) at different levels on the grain yield and physiological characteristics of rice plants during grain filling period. Two cultivars, Ningjing 1 (TCB sensitive) and Yangfujing 8 (TCB tolerant), were planted in soils containing 0 (CK), 10, 20, 40 and 80 mg TCB per kg soil. Significant differences were determined in the effects of TCB levels on the grain yield and physiological characteristics during grain filling period between the two cultivars. With the increase in TCB level, the yield of Ningjing 1 was reduced gradually and the yield of Yangfujing 8 was increased at the two low TCB levels of 10 and 20 mg/kg and significantly decreased at higher TCB levels. At the medium and high TCB levels (40 and 80 mg/kg), the panicle number per pot, grain number per panicle and seed setting rate of Ningjing 1 decreased significantly, with decrements significantly bigger than Yangfujing 8, while there was no significant difference in 1000-grain-weight between TCB treatments. The plant height and dry biomass weight of Ningjing 1 were reduced at higher degrees than those of Yangfujing 8. At the low TCB level (20 mg/kg), chlorophyll content, root activity and soluble protein were significantly decreased in the leaves of Ningjing 1and slightly increased in the leaves of Yangfujing 8. The activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) of the leaves of two cultivars in leaves were increased at low TCB levels and decreased at high TCB levels. At the low TCB levels of 10 and 20 mg/kg, the activities of antioxidant enzymes in Yangfujing 8 were significantly higher than in Ningjing 1. At the highest level of 80 mg/kg, the activities of antioxidant enzymes were significantly lower as compared with the control, with bigger decrements than those in Yangfujing 8. The content of MDA in leaves of Ningjing 1 increased more remarkably than that in Yangfujing 8, indicating that lipid peroxidation was more serious in Ningjing 1. Our study indicated that low TCB levels slightly promoted rice yield, biomass weight, chlorophyll content, protein content and the activities of antioxidant enzymes of the leaves of Yangfujing 8. TCB at the medium and high levels had more inhibitive effects on Ningjing 1 than on Yangfujing 8. Compared with Ningjing 1, Yangfujing 8 was more resistant and adaptable to TCB at different levels.