Eleven barnyardgrass populations were assayed. The highest resistant population was Geqiushan R with RI 125.45 resulted from the seed assay and 87.29 resulted from the whole plant bioassay followed by 853 R with RI 2....Eleven barnyardgrass populations were assayed. The highest resistant population was Geqiushan R with RI 125.45 resulted from the seed assay and 87.29 resulted from the whole plant bioassay followed by 853 R with RI 2.79 resulted from the seed assay and 6.04 resulted from the whole plant bioassay. The resistance level of other nine populations was low with RI 1.13-2.61 resulted from the seed assay and 1.48-3.63 resulted from the whole plant bioassay. The activity of an important metabolic enzyme glutathione S-transferases （GSTs） and three protective enzymes （SOD, POD, and CAT） were determined in vivo for Geqiushan R, 853 R, and Wudalianchi R. Compared with the S controls, the activities of POD in Geqiushan R, GSTs in 853 R, and Wudalianchi R were increased.展开更多
The possibility of gene flow between two varieties of transgenic rice with bar gene (Y0003 and 99-t) (male) and barnyard grass(Echinochloa crusgalli var. mitis ) (female) was studied by means of reproductive biology. ...The possibility of gene flow between two varieties of transgenic rice with bar gene (Y0003 and 99-t) (male) and barnyard grass(Echinochloa crusgalli var. mitis ) (female) was studied by means of reproductive biology. The germination and growth of rice pollen grains on barnyard grass stigmas at 30 min, and 1-4 h after crossing by hand were observed with an optical microscope. The results were compared with the germination and growth of barnyard grass pollen grains at the corresponding time after self-pollination. The results showed that germination and growth of the pollen grains of the two varieties were similar on barnyard grass stigmas, but differed significantly from self-pollination of barnyard grass. Pollen grains germinated and pollen tubes penetrated stigmas normally, and the number of pollen grains being condensing or releasing their inclusions or having released them increased with the time after self-pollination. Pollen grains of transgenic rice on the stigmas of barnyard grass couldn't germinate or grow normally after crossing, neither could they penetrate the stigmas of barnyard grass. Therefore, it could be concluded that the sexual incompatibility between transgenic rice with bar gene and barnyard grass is due to the rice pollen being unable to penetrate the stigma of barnyard grass. Further proof of incompatibility lies in the fact that the emasculated barnyard grass pollinated with the rice pollen grains could not seed.展开更多
[Objectives]This study was conducted to screen the resistance of Echinochloa crusgalli in some paddy fields in Changde City,Yiyang City and Yueyang City in Hunan Province to penoxsulam and bispyribac-sodium.[Methods]T...[Objectives]This study was conducted to screen the resistance of Echinochloa crusgalli in some paddy fields in Changde City,Yiyang City and Yueyang City in Hunan Province to penoxsulam and bispyribac-sodium.[Methods]The resistance to penoxsulam and bispyribac-sodium was screened in 11 E.crusgalli populations collected from rice production areas in Changde,Yiyang and Yueyang Cities,Hunan Province,and the resistance level of population HU-2 to penoxsulam was determined.[Results]HU-1 to HU-6 and HU-8 A,a total of seven populations showed high levels of resistance to penoxsulam and bispyribac-sodium.The resistance level of population HU-2 to penoxsulam was extremely high;population HU-7 showed low-level resistance to both drugs;HU-11 population showed low-level resistance to penoxsulam and was susceptible to bispyribac-sodium;and populations HU-8 and HU-9 were susceptible to penoxsulam and bispyribac-sodium.[Conclusions]This study provides a technical basis for the rational use of penoxsulam and bispyribac-sodium and the selection of control chemicals for E.crusgalli in paddy fields.展开更多
The present work aimed to evaluate the effect of different water stress levels on the development of both rice and barnyardgrass. The study was established into greenhouse, in completely randomized design, in factoria...The present work aimed to evaluate the effect of different water stress levels on the development of both rice and barnyardgrass. The study was established into greenhouse, in completely randomized design, in factorial scheme 2 × 5, with four replications. Factor “A” comprised the plant species (rice cv. BRS Querência, or the weed Echinochloa crusgalli), and factor “B” comprised the water stress levels: (T1) continuous flood (CF);(T2) 0 kPa (saturated soil);(T3) 10 kPa;(T4) 40 kPa;and (T5) 100 kPa. Plant emergence was assessed every day;plant length was measured 30 days after planting. At the end of the experiment, the number of leaves per plant, root length and shoot and root dry mass were determined. Our data supply evidence that under moderate water stress, up to approximately 40 kPa, rice tends to perform better than barnyardgrass in the initial stage of crop growth, when under equivalent plant density. However, barnyardgrass is usually present in much higher plant density than crop plants in fields traditionally cropped with rice. Thus, efficient control of barnyardgrass should be accomplished to avoid damage to rice crop by competition for environmental resources.展开更多
稗草是中国南方双季稻稻田的恶性杂草，对水稻生产造成严重威胁。为明确稗草对双季稻生长的影响及其经济危害允许水平，采用添加系列试验和模型拟合的方法研究了不同稗草密度下水稻生长与产量性状的变化规律。结果表明，在稗草的竞争干...稗草是中国南方双季稻稻田的恶性杂草，对水稻生产造成严重威胁。为明确稗草对双季稻生长的影响及其经济危害允许水平，采用添加系列试验和模型拟合的方法研究了不同稗草密度下水稻生长与产量性状的变化规律。结果表明，在稗草的竞争干扰下，双季早、晚稻的株高、分蘖数、有效穗数、每穗实粒数、千粒重及产量均随稗草密度的增加而逐渐降低。指数模型 y ＝beax 可以较好地拟合稗草对早稻分蘖数、有效穗数和产量的影响，而二次曲线模型 y ＝ax 2＋bx＋c 拟合稗草与株高、每穗实粒数、千粒重和产量损失间的关系最佳；二次曲线模型 y ＝ax 2＋bx＋c 均可较好地拟合稗草与晚稻株高、分蘖数、有效穗数、每穗实粒数、千粒重、产量和产量损失间的关系。稻田使用化学除草剂（丁草胺、二氯喹啉酸、五氟磺草胺）防除时，双季早、晚稻稻田稗草的经济危害水平分别为1．64％～2．91％和1．28％～2．28％，经济阈值分别为0．63～1．23株／m^2和1．30～1．85株／m^2。稗草对水稻生长有抑制作用，并导致水稻产量损失；通过对经济阈值分析，化学除草剂防治稗草具有明显的经济优势。展开更多
基金supported by the Ph D Programs Foundation of Ministry of Education of China(20093702110003)the National Key Technology R&D Program of China (2006BAD08A09)
文摘Eleven barnyardgrass populations were assayed. The highest resistant population was Geqiushan R with RI 125.45 resulted from the seed assay and 87.29 resulted from the whole plant bioassay followed by 853 R with RI 2.79 resulted from the seed assay and 6.04 resulted from the whole plant bioassay. The resistance level of other nine populations was low with RI 1.13-2.61 resulted from the seed assay and 1.48-3.63 resulted from the whole plant bioassay. The activity of an important metabolic enzyme glutathione S-transferases （GSTs） and three protective enzymes （SOD, POD, and CAT） were determined in vivo for Geqiushan R, 853 R, and Wudalianchi R. Compared with the S controls, the activities of POD in Geqiushan R, GSTs in 853 R, and Wudalianchi R were increased.
基金the Ministry ofScience and Technology,P.R.ChinaEvaluation of Safety of Transgenic Crops(E200102).
文摘The possibility of gene flow between two varieties of transgenic rice with bar gene (Y0003 and 99-t) (male) and barnyard grass(Echinochloa crusgalli var. mitis ) (female) was studied by means of reproductive biology. The germination and growth of rice pollen grains on barnyard grass stigmas at 30 min, and 1-4 h after crossing by hand were observed with an optical microscope. The results were compared with the germination and growth of barnyard grass pollen grains at the corresponding time after self-pollination. The results showed that germination and growth of the pollen grains of the two varieties were similar on barnyard grass stigmas, but differed significantly from self-pollination of barnyard grass. Pollen grains germinated and pollen tubes penetrated stigmas normally, and the number of pollen grains being condensing or releasing their inclusions or having released them increased with the time after self-pollination. Pollen grains of transgenic rice on the stigmas of barnyard grass couldn't germinate or grow normally after crossing, neither could they penetrate the stigmas of barnyard grass. Therefore, it could be concluded that the sexual incompatibility between transgenic rice with bar gene and barnyard grass is due to the rice pollen being unable to penetrate the stigma of barnyard grass. Further proof of incompatibility lies in the fact that the emasculated barnyard grass pollinated with the rice pollen grains could not seed.
基金Supported by Science and Technology Innovation Program of Hunan Province(2019NK4170)Research Innovation Program for College Graduates of Hunan Province(CX2018B796)。
文摘[Objectives]This study was conducted to screen the resistance of Echinochloa crusgalli in some paddy fields in Changde City,Yiyang City and Yueyang City in Hunan Province to penoxsulam and bispyribac-sodium.[Methods]The resistance to penoxsulam and bispyribac-sodium was screened in 11 E.crusgalli populations collected from rice production areas in Changde,Yiyang and Yueyang Cities,Hunan Province,and the resistance level of population HU-2 to penoxsulam was determined.[Results]HU-1 to HU-6 and HU-8 A,a total of seven populations showed high levels of resistance to penoxsulam and bispyribac-sodium.The resistance level of population HU-2 to penoxsulam was extremely high;population HU-7 showed low-level resistance to both drugs;HU-11 population showed low-level resistance to penoxsulam and was susceptible to bispyribac-sodium;and populations HU-8 and HU-9 were susceptible to penoxsulam and bispyribac-sodium.[Conclusions]This study provides a technical basis for the rational use of penoxsulam and bispyribac-sodium and the selection of control chemicals for E.crusgalli in paddy fields.
文摘The present work aimed to evaluate the effect of different water stress levels on the development of both rice and barnyardgrass. The study was established into greenhouse, in completely randomized design, in factorial scheme 2 × 5, with four replications. Factor “A” comprised the plant species (rice cv. BRS Querência, or the weed Echinochloa crusgalli), and factor “B” comprised the water stress levels: (T1) continuous flood (CF);(T2) 0 kPa (saturated soil);(T3) 10 kPa;(T4) 40 kPa;and (T5) 100 kPa. Plant emergence was assessed every day;plant length was measured 30 days after planting. At the end of the experiment, the number of leaves per plant, root length and shoot and root dry mass were determined. Our data supply evidence that under moderate water stress, up to approximately 40 kPa, rice tends to perform better than barnyardgrass in the initial stage of crop growth, when under equivalent plant density. However, barnyardgrass is usually present in much higher plant density than crop plants in fields traditionally cropped with rice. Thus, efficient control of barnyardgrass should be accomplished to avoid damage to rice crop by competition for environmental resources.
文摘稗草是中国南方双季稻稻田的恶性杂草，对水稻生产造成严重威胁。为明确稗草对双季稻生长的影响及其经济危害允许水平，采用添加系列试验和模型拟合的方法研究了不同稗草密度下水稻生长与产量性状的变化规律。结果表明，在稗草的竞争干扰下，双季早、晚稻的株高、分蘖数、有效穗数、每穗实粒数、千粒重及产量均随稗草密度的增加而逐渐降低。指数模型 y ＝beax 可以较好地拟合稗草对早稻分蘖数、有效穗数和产量的影响，而二次曲线模型 y ＝ax 2＋bx＋c 拟合稗草与株高、每穗实粒数、千粒重和产量损失间的关系最佳；二次曲线模型 y ＝ax 2＋bx＋c 均可较好地拟合稗草与晚稻株高、分蘖数、有效穗数、每穗实粒数、千粒重、产量和产量损失间的关系。稻田使用化学除草剂（丁草胺、二氯喹啉酸、五氟磺草胺）防除时，双季早、晚稻稻田稗草的经济危害水平分别为1．64％～2．91％和1．28％～2．28％，经济阈值分别为0．63～1．23株／m^2和1．30～1．85株／m^2。稗草对水稻生长有抑制作用，并导致水稻产量损失；通过对经济阈值分析，化学除草剂防治稗草具有明显的经济优势。
