In order to study the regeneration technology of mature embryos in different rice varieties,nine japonica,nine indica and eleven hybrid rice varieties of two line or three line or superiority combinations were selecte...In order to study the regeneration technology of mature embryos in different rice varieties,nine japonica,nine indica and eleven hybrid rice varieties of two line or three line or superiority combinations were selected as explants to study the callus induction,differentiation and regeneration rates on different media.The higher callus induction （61.7-89.2%） was observed in japonica rice,when cytokinin was added at lower concentration （0.3 mg L-1 6-BA） in M8 basal medium,supplemented with 30 g L-1 sucrose,8 g L-1 agar and 2 mg L-1 2,4-D.Further,the addition of two cytokinins （2 mg L-1 6-BA,0.5 mg L-1 KT） and 1 mg L-1 NAA in the M8 basal supplemented medium resulted in 9.1-100% of the callus induction in indica rice.The percent callus induction in hybrid rice varieties was 40-86.3% when addition of 1 mg L-1 6-BA and 1 mg L-1 KT was added,and the cytokinins was required by the japonica and indica rice varieties in the M8 basal supplemented medium.It was observed that when the 0.5 mg L-1 2,4-D and 1 mg L-1 6-BA were added in japonica rice,and 0.2 mg L-1 2,4-D and 0.5 mg L-1 6-BA were added in indica and hybrid rice in the MS different media,the regeneration rates were 9.2-59.5%,3.6-87.5% and 17.2-43.2% for japonica,indica and hybrid rice,respectively.Thus,the regeneration technology with higher output is established in the mature embryos of similar rice varieties.展开更多
Panicles of an indica rice line TM7-5 were subjected to radiation with 137^Cs gamma rays at 0 （control）, 5, 10, 15 and 20 Gy respectively, and then its anthers were cultured. There were slight differences among the ...Panicles of an indica rice line TM7-5 were subjected to radiation with 137^Cs gamma rays at 0 （control）, 5, 10, 15 and 20 Gy respectively, and then its anthers were cultured. There were slight differences among the treatments in peak emerging time of callus initiation, from 38 to 44 days after inoculation （DAI） as well as the frequency of callus initiation （2.3-3.5%）. About two thirds calli were induced before 44 DAI, and calli derived beyond 60 DAI lost the regeneration ability. Green plant regeneration frequency was significantly stimulated from two- to three-fold by irradiation of the 1370S gamma rays compared with the control, and the maximum was 22,81% （15 Gy）. The culture ability based on callus initiation and green plantlet regeneration was 0.19% for the control while it was over 0.45% for all the irradiated treatments, and the maximum was 0,59% for 15 Gy treatment. The advantages of panicle irradiation before anther culture and the potential application in rice anther culture, especially for recalcitrant indica rice, were discussed.展开更多
College English teaching aims to cultivate the students＇ language applying competence, to help them broaden their mind, to absorb in foreign cultural essence and to improve cultural accomplishment. For college studen...College English teaching aims to cultivate the students＇ language applying competence, to help them broaden their mind, to absorb in foreign cultural essence and to improve cultural accomplishment. For college students, acquiring reading comprehension ability plays an essential part in understanding cultural distinctions and communicating effectively. However, the truth is that their reading comprehension ability and language applying competence prove not very optimistic. Therefore, the Present paper gives some insight to teachers on how reading English should be taught more effectively to college students.展开更多
基金supported by the National Natural Science Foundation of China (30871459)the Key Project of Cultivate New Varieties of Genetically Modified Technology of China (2008ZX08001-004)+1 种基金the Agricultural Science and Technology Innovation Fundation of Jiangsu Province, China (CX[07]603)the Fundation of Jiangsu Academy of Agricultural Sciences, China (6510707 and 6110704)
文摘In order to study the regeneration technology of mature embryos in different rice varieties,nine japonica,nine indica and eleven hybrid rice varieties of two line or three line or superiority combinations were selected as explants to study the callus induction,differentiation and regeneration rates on different media.The higher callus induction （61.7-89.2%） was observed in japonica rice,when cytokinin was added at lower concentration （0.3 mg L-1 6-BA） in M8 basal medium,supplemented with 30 g L-1 sucrose,8 g L-1 agar and 2 mg L-1 2,4-D.Further,the addition of two cytokinins （2 mg L-1 6-BA,0.5 mg L-1 KT） and 1 mg L-1 NAA in the M8 basal supplemented medium resulted in 9.1-100% of the callus induction in indica rice.The percent callus induction in hybrid rice varieties was 40-86.3% when addition of 1 mg L-1 6-BA and 1 mg L-1 KT was added,and the cytokinins was required by the japonica and indica rice varieties in the M8 basal supplemented medium.It was observed that when the 0.5 mg L-1 2,4-D and 1 mg L-1 6-BA were added in japonica rice,and 0.2 mg L-1 2,4-D and 0.5 mg L-1 6-BA were added in indica and hybrid rice in the MS different media,the regeneration rates were 9.2-59.5%,3.6-87.5% and 17.2-43.2% for japonica,indica and hybrid rice,respectively.Thus,the regeneration technology with higher output is established in the mature embryos of similar rice varieties.
文摘Panicles of an indica rice line TM7-5 were subjected to radiation with 137^Cs gamma rays at 0 （control）, 5, 10, 15 and 20 Gy respectively, and then its anthers were cultured. There were slight differences among the treatments in peak emerging time of callus initiation, from 38 to 44 days after inoculation （DAI） as well as the frequency of callus initiation （2.3-3.5%）. About two thirds calli were induced before 44 DAI, and calli derived beyond 60 DAI lost the regeneration ability. Green plant regeneration frequency was significantly stimulated from two- to three-fold by irradiation of the 1370S gamma rays compared with the control, and the maximum was 22,81% （15 Gy）. The culture ability based on callus initiation and green plantlet regeneration was 0.19% for the control while it was over 0.45% for all the irradiated treatments, and the maximum was 0,59% for 15 Gy treatment. The advantages of panicle irradiation before anther culture and the potential application in rice anther culture, especially for recalcitrant indica rice, were discussed.
文摘College English teaching aims to cultivate the students＇ language applying competence, to help them broaden their mind, to absorb in foreign cultural essence and to improve cultural accomplishment. For college students, acquiring reading comprehension ability plays an essential part in understanding cultural distinctions and communicating effectively. However, the truth is that their reading comprehension ability and language applying competence prove not very optimistic. Therefore, the Present paper gives some insight to teachers on how reading English should be taught more effectively to college students.
