水稻育性调控的分子遗传研究进展

杂交水稻为世界粮食安全做出了重要贡献。细胞质雄性不育和光/温敏不育分别是三系和两系杂交稻生产利用的遗传基础,而(亚)种间杂种不育则是杂交稻生产中要克服的主要技术瓶颈。因此,水稻育性调控是杂交水稻生产技术的关键,也是研究植物核质互作和物种生殖隔离等基础科学问题的重要模型。我国植物遗传学家在阐明杂交水稻育性调控的分子遗传基础领域做出了重要贡献。本文回顾了我国杂交水稻的发展历程,系统总结了杂交水稻生产涉及的细胞质雄性不育与恢复、光/温敏不育与育性转换、杂种不育与亲和性的遗传基础和分子作用机制,探讨了我国杂交水稻生产存在的问题,指明了水稻杂种优势利用的发展方向。

Correlation between Stigma Characteristics and Outcrossing Rate of Five Photo-thermo Sensitive Genic Male Sterile(PTGMS) Rice Lines

[Objective] This study aimed to investigate the correlation between stigma characteristics and outcrossing rate of photo-thermo sensitive genic male sterile（PTGMS） rice lines. [Method] The stigma exsertion rate, stigma size and stigma vitality of Chuang 5S, Yun 9S, Peiai 64 S, P88 S and Y58 S were analyzed. Using R608 as a male parent, outcrossing rate of these five PTGMS lines was determined. [Result]There were differences in stigma exsertion rate, stigma size and stigma vitality among five PTGMS lines. P88 S exhibited the best stigma characteristics and relatively strong stigma vitality, with the stigma exsertion rate of 95.94%, stigma vitality coefficient of 2.71, outcrossing rate of 84.02% in the field. Peiai 64 s had the minimum stigma length（2.41 mm） and stigma width（1.10 mm） and the weakest stigma vitality, with the stigma exsertion rate of 93.04%, outcrossing rate of 65.47%. Yun 9S,Y58 S and Chuang 5S displayed medium stigma characteristics, among which Yun9 S exhibited higher outcrossing rate than other two PTGMS lines. Correlation analysis showed that stigma exsertion rate, stigma length, stigma width, stigma area and stigma volume were significantly correlated to outcrossing rate（P〈0.05）, with correlation coefficients of 0.897, 0.934, 0.934, 0.939 and 0.937, respectively. However,there was no significant correlation between stigma vitality coefficient and outcrossing rate. [Conclusion] Based on stigma characteristics of five PTGMS lines, auxiliary pollination measures should be adopted reasonably to save production costs and improve hybrid rice seed yield.

Study on Seed Vigor of Rice Photo-ThermoSensitive Genic Male Sterile(PTGMS) Line with Low Temperature Storage

To explore the change rule of seed vigor and seed application technology of rice PTGMS lines with low temperature storage,Zhun S,Y58S,Feng S and Guangzhan 63-4S stored in the seed bank with the temperature of 8-10 ℃ and with the relative humidity of 55% for different years were used as the materials to study the properties of seed vigor,growth and development in the field, etc. The re- sults showed that the germination potential, germination rate, germination index and vigor index of rice PTGMS lines seeds showed downward trends as the time of low temperature storage prolonged,and all of the germination rates of the seeds within five years were over 60%. The conductivity in the soaked solution of seeds was significantly increased with the prolonged low temperature storage time. Seedling rate,root length,white root number,base stem width and seedling dry weight of seeds showed downward trends as the time of low temperature storage prolonged. There was no significant difference between two integral seedling qualities of seeds within 4-6 years in low temperature storage. Compared with the germination rate of low temperature storage seeds soaking for 6,12 and 24 h,the appropriate soak time of long time low temperature storage or low vigor seeds was 12 h. A serious natural aging phenomenon occurred in low temperature storage seeds after out of the storage. The germination rate of seeds placed under natural condition for 50 d decreased obviously. The duration from seeding to heading of Zhun S,Y58S and Feng S shortened as the time of low temperature storage prolonged, while the vari- ation of panicle duration of all PTGMS lines was not obvious. In conclusion, rice PTGMS line seeds with low temperature storage in 5 years could still be used nor- mally. However.seeds after low temperature storage should be sowed as soon as possible, and the soaking time of low vigor seeds should be shortened,and the possibility that the decreased duration from seeding to heading should also be con- sidered.

Comparative Studies on the Changes of Microtubule Distribution and Reorganization During the Meiotic Stages of Development in Normal (IR36) and a Temperature/photoperiod Sensitive Male Sterile Line (Peiai 64S) of Rice ( Oryza sativa )

Changes in the pattern of organization of microtubules in the meiotic stages of development of pollen (i.e. from pre-meiotic interphase to more or less metaphase I) of a normal (IR36) and a temperature/photoperiod sensitive male sterile line (Peiai 64S) of rice were studied using immunofluorescence confocal microscopy. In IR36, from pre-meiotic interphase to metaphase I, the pattern of microtubule distribution in the meiocytes underwent a series of changes. Some new organizational patterns of microtubules (that have not been described before) were observed during microsporogenesis, including the existence of a broad band of perinuclear microtubules at the diakinesis stage of development. The pattern of microtubule distribution in the meiocytes of the male sterile line, Peiai 64S, was quite different front that seen in IR36. In Peiai 64S, the microtubules showed abnormal patterns of distribution from pre-meiotic interphase to metaphase I. For example the broad band of perinuclear microtubules seen at diakinesis in IR36 was much disorganized and loosened in Peiai 64S. The spindles formed were also very abnormal and different from the normal spindle. The appearance of abnormal microtubule distribution in the early stages of microsporogenesis may contribute to the malformation and ultimate abortion of pollen in Peiai 64S.

Research on a Method for Purification and Multiplication of PTGMS Lines

[Objective] The aims was to explore PTGMS line purification and multipli- cation technology. [Method] Three commercial PTGMS lines, Annong 810S, P88S and C815S, were used in this study. In the first year, two sterile line populations with same genetic background were multiplied by dividing seedling; meanwhile, se- lection and multiplication of the core individuals were conducted; within the year, the core seeds harvested were multiplied under the isolated condition in Hainan, and at the same time, superior individuals were selected and used as the seeds for two populations with same genetic background in the next year. In the second year, seeds harvested in Hainan were planted in Changsha, while the core individuals were selected and multiplied; the core seeds harvested were continued to multiply in Hainan. The above procedures were repeated in the following years. [Result] The test results showed that in two years the proportion of core individuals in the popu- lation of Annong 810S, P88S and C815S increased from 40.3%, 0.7% and 0.3% in the first year to 71.67%, 66.00% and 68.67% in the second year respectively. [Conclusion] This suggested that this method of purification and multiplication of the PTGMS lines for consecutive years can effectively control the drift of the critical sterility inducing temperature, and at the same time, core seeds with high purity and controlled inducing temperature can be harvested.

Breeding and Application of Indica PTGMS Line Yan 161S and Its Hybrid Yanliangyou 1618 in Rice

In 2006, the indica photoperiod- and thermo-sensitive genic male sterile （PTGMS） line Yan 161S was successful y bred by crossing the Guangzhan 63S （♀） and the medium indica breeding material Yan 229 （♂）, which was bred by the Institute of Agricultural Sciences in Coastal Region of Jiangsu Province, after years＇ and generations’ selection in different areas. It passed the identification by Jiangsu Provincial Crop Variety Appraisal Committee in 2013. Crossing the Yan 161S with Yanhui 888, a new high-yielding and high-quality two-line hybrid rice combination Yanliangyou 1618 was developed, and it passed the variety identification in 2014. This paper introduced the breeding processes and characteristics of Yan 161S and Yanliangyou 1618 and the cultivation and seed production techniques of Yanliangyou 1618.

Effect of High Temperature on Outcrossing Characteristics at the Fertility Sensitive Period of Photo-thermo Sensitive Genic Male Sterile (PTGMS) Rice Lines

Four sterile lines （Peiai64S, Y58S, Guangzhan 63-2S and H638S） and the restoring line R527 were used as materials. Five temperature gradients （24, 27, 30, 33 and 36 ℃ in artificial climate chamber） and the natural temperature （as control） were treated to the four sterile lines for 6 d in the fertility sensitive period of heading to flowering stage, respectively, to study the effects of temperature on physiological biochemical characteristics of young panicles and outcrossing characteristics. The results showed that the percentages of exerted stigma of Peiai 64S and Y58S were the highest at 27 ℃, which were 86.81% and 86.06%, respectively, while the percentages of exerted stigma of Guangzhan 63-2S and H638S were the highest at 24 ℃, which were 76.24% and 81.76%, respectively; the stigma viability of Peiai 64S, Y58S, Guangzhan 63-2S and H638S were the best at 24 ℃, which were 1.96, 2.12, 1.74 and 1.94, respectively; the outcrossing rates of Peiai 64S, Guangzhan 63-2S and H638S were the highest at 24 ℃, which were 58.87%, 54.22% and 50.50%, respectively, while the outcrossing rate of Y58S was the highest at 27 ℃, which was 58.96%; and the contents of peroxidase （POD） of the four sterile lines increased significantly at 33 ℃ compared with the control, while the contents of malondialdehyde （MDA） and proline increased significantly at 36 ℃ compared with the control. There were differences in temperature sensitivity between the male sterile lines, and the 24 ℃ treatment during the sensitive period was the best for the fertility sensitive period of Peiai 64S, while 27 ℃ was the best temperature for Y58S, Gangzhan 63-2S and H638S.

Preliminary Study on Inheritance of Stigma Exertion in Wheat Thermo-photo Sensitive Genic Male Sterile Line

Stigma exertion is one of the key factors for improving the outcrossing ability of wheat thermo-photo sensitive genic male sterile（TPSGMS） line. A DH population derived from K239S/K92 S was constructed to investigate the inheritance of stigma exertion. K239 S and K92 S are TPSGMS lines with higher and lower stigma exertion rates（SER）, respectively. The SERs of parents, reciprocal crosses and the DH population were evaluated for two consecutive years. The results showed that no significant difference was observed in SER between F1 s of K239S/K92 S and K92S/K239 S,implying that stigma exertion was a trait controlled by nuclear gene（s）. In the DH population, the segregation of low and high SERs fitted to a ratio of 3 ∶1 by Chisquare test, suggesting that the stigma exertion of K239 S was controlled by one pair of recessive genes. In addition, the effects of temperature and humidity on the expression of stigma exertion were also discussed.

Breeding and Application of Indica PTGMS Line Yan 220S in Rice

Yan 220S, which is derived from a natural variant plant discovered among the population of Guangzhan 63S and developed by Jiangsu Agricultural Research Institute for Coastal Regions through pedigree selection over years, is an indica photo- and thermo-sensitive genic male sterile （PTGMS） line in rice. In 2013, it was technically identified by Jiangsu Crop Variety Appraisal Committee. Its hybrid Yan-liangyou 2208 （Yan 220S/Yanhui 888）, a new two-line hybrid rice combination with high yield and good grain quality, was subsequently developed and released for commercial production by the National Crop Variety Appraisal Committee in 2013.