Seed aging characteristics of rice was investigated in this study. Seeds of 34 japonica rice (O-ryza sativa subsp. japonica) varieties were held at 451 constant temperature. Changes in seed viability and seed vigor du...Seed aging characteristics of rice was investigated in this study. Seeds of 34 japonica rice (O-ryza sativa subsp. japonica) varieties were held at 451 constant temperature. Changes in seed viability and seed vigor during aging process were measured to study seed viability-losing characteristic and to determine warning index for seed viability loss. As a result, seed viability survival curves were obtained across different rice accessions at 45℃ constant temperature. The curves appeared to be contra-sigmoid survival curves. The loss of seed viability in the aging process consisted of two phases. The first phase took a long duration, in which the viability of vigorous seeds declined slowly. In the second phase, seed viability declined rapidly. It was obvious that seed viability declined inconsistently during storage. It also showed that seed germination was prolonged and the seedling was significantly weakened before the coming of the rapid declining phase of seed viability. These two parameters could be used to indicate seed quality during storage. The rate of compatibility of tests (RCT), coefficient of variation (CV), vigor of seedling, the day the seeds start to germinate could be used as warning indexes to indicate overall quality of a mass of accessions. These warning indexes could also be used in monitoring the viability of seeds stored in the seed genebank.展开更多
Real-time monitoring and investigation in fields showed that the disease starting period of Sclerotinia sclerotiorum in mechanical direct seeding fields was earlier. Disease conditions rose with the advancing growth s...Real-time monitoring and investigation in fields showed that the disease starting period of Sclerotinia sclerotiorum in mechanical direct seeding fields was earlier. Disease conditions rose with the advancing growth stage, which grew more quickly during the early stage of anthesis, flower withering period and early si- lique mature period. Yield less rate increased with the increasing stem disease rate and disease index. Yield loss rate（ Y1 ） had extremely significant correlation with stem disease rate（X1 ）and disease index（X2 ）, and the related models were Y1 = 0. 544 330 2X1 -2. 316 1 （n = 14, r --0. 986 0 ＊ ＊ ）and YI = 0. 673 408 X2 - 1. 016 4 （ n = 14 ,r = 0.977 2 ~ ＊ ）, respectively. Disease control indexes for one time control against S. sclerotlorum in mechanical direct seeding fields were stem disease rate as 11.8% and disease index as 7.6, respectively. The control indexes for twice control against the disease were stem disease rate as 16.8% and disease index as 11.7. This paper provided a new scientific basis for preventing S. sclerotiorum in mechanical direct seeding fields.展开更多
文摘Seed aging characteristics of rice was investigated in this study. Seeds of 34 japonica rice (O-ryza sativa subsp. japonica) varieties were held at 451 constant temperature. Changes in seed viability and seed vigor during aging process were measured to study seed viability-losing characteristic and to determine warning index for seed viability loss. As a result, seed viability survival curves were obtained across different rice accessions at 45℃ constant temperature. The curves appeared to be contra-sigmoid survival curves. The loss of seed viability in the aging process consisted of two phases. The first phase took a long duration, in which the viability of vigorous seeds declined slowly. In the second phase, seed viability declined rapidly. It was obvious that seed viability declined inconsistently during storage. It also showed that seed germination was prolonged and the seedling was significantly weakened before the coming of the rapid declining phase of seed viability. These two parameters could be used to indicate seed quality during storage. The rate of compatibility of tests (RCT), coefficient of variation (CV), vigor of seedling, the day the seeds start to germinate could be used as warning indexes to indicate overall quality of a mass of accessions. These warning indexes could also be used in monitoring the viability of seeds stored in the seed genebank.
基金Supported by Agricultural Key Projects of Science and Technology Plan of Taizhou City(102KY03)
文摘Real-time monitoring and investigation in fields showed that the disease starting period of Sclerotinia sclerotiorum in mechanical direct seeding fields was earlier. Disease conditions rose with the advancing growth stage, which grew more quickly during the early stage of anthesis, flower withering period and early si- lique mature period. Yield less rate increased with the increasing stem disease rate and disease index. Yield loss rate（ Y1 ） had extremely significant correlation with stem disease rate（X1 ）and disease index（X2 ）, and the related models were Y1 = 0. 544 330 2X1 -2. 316 1 （n = 14, r --0. 986 0 ＊ ＊ ）and YI = 0. 673 408 X2 - 1. 016 4 （ n = 14 ,r = 0.977 2 ~ ＊ ）, respectively. Disease control indexes for one time control against S. sclerotlorum in mechanical direct seeding fields were stem disease rate as 11.8% and disease index as 7.6, respectively. The control indexes for twice control against the disease were stem disease rate as 16.8% and disease index as 11.7. This paper provided a new scientific basis for preventing S. sclerotiorum in mechanical direct seeding fields.
