The narrow genetic base in potato (Solanum tuberosum L.) limits the progress in cultivar development.The rich diploid germplasm in the origin center of potato provide a unique resource for improvement of tetraploid po...The narrow genetic base in potato (Solanum tuberosum L.) limits the progress in cultivar development.The rich diploid germplasm in the origin center of potato provide a unique resource for improvement of tetraploid potatoes.Seven newly developed diploid hybrids with 2n pollen production,all of which have S. phureja background,were developed and evaluated for their value in potato breeding.They were crossed as male parnets to six tetraploid Solanum tuberosum cultivars,and seeds in large quantity from eleven crosses were obtained.Main agronomic traits,such as tuber yield,tuber number,mean tuber weight,tuber shape,eye depth,skin smoothness,flesh color,and specific gravity,were measured for 4x 2x tetraploid progenies in seedling generation,and their parents as well.All of the diploid hybrids had some merit for specific traits and the DH39 was more promising;high specific gravity trait in some diploid hybrids was successfully introgressed into tetroploid progenies via 4x 2x crosses.These diploid hybrids have potential value in potato breeding.展开更多
In 1988, we found strain 9003 from compositehybridization of indica and japonica. 9003 pos-sesses characteristics of twin seedlings withfrequency of 15-20% of the investigated popu-lation. The highest frequency was 45...In 1988, we found strain 9003 from compositehybridization of indica and japonica. 9003 pos-sesses characteristics of twin seedlings withfrequency of 15-20% of the investigated popu-lation. The highest frequency was 45.68%.Afterwards, we discovered that some twinseedlings had variabilities in chromosome set.As to a pair of twin plants, it may be 2n-1n,2n-3n, 3n-3n or 1n-1n. The changes in chro-mosome set also occurred in the plants devel-oped from mono-embryo seeds. All of thesevariants nearly account for 1% in our con-trolled experiment. We named the triploidplants SAR-3 and found that SAR-3 could be aresource of diploid true breeding hybrid rice.展开更多
As maternal parents, diploid （L202-2x） and autotetraploid （L202-4x） of Oryza sativa cv. L2O2 were crossed with O. officinalis. Embryo development and fertilization in these two crosses were comparatively studied. ...As maternal parents, diploid （L202-2x） and autotetraploid （L202-4x） of Oryza sativa cv. L2O2 were crossed with O. officinalis. Embryo development and fertilization in these two crosses were comparatively studied. There were no mature hybrid seeds obtained because all the hybridized spikelets died 30 days after pollination. The main reasons for no seed set were abnormal fertilization and development of the embryos and endosperms in the interspecific hybrids. There were doublefertilization, egg cell single-fertilization and non-fertilization in these crosses. Although 59.45% and 54.87% of hybrid embryos produced in the crosses of L202-2x/O. officinalis and L202-4x/O. officinalis, respectively, hybrid embryos ceased to develop or degenerated and plenty of free endosperm nuclei were in disaggregating state without developing cellular endosperms three days after pollination. Besides, some embryological differences in these two crosses were found, that is, the rate of double-fertilization and total rate of doubleand single-fertilization in L202-2x/O. officinalis were higher than those in L202-4x/O. officinalis. The embryo and endosperm of hybrids developed more slowly, and embryos and free endosperm nuclei were more severely degenerated in L202-4x/O. officinalis than in L202-2x/O. officinalis. Five days after pollination, a few of embryos in L202-2x/O. officinalis developed into pear-shaped ones, however, embryos in L202-4x/O. officinalis were all degenerated. Therefore, it is more difficult to obtain interspecific hybrids by wide crosses between autotetraploid of O. sativa and O. officinalis.展开更多
对杂交三倍体泥鳅Misgurnus anguillicaudatus(2n♀×4n♂,DT)和二倍体泥鳅(2n♀×2n♂,DD)的胚胎发育进行观察,详细记录了其胚胎发育的形态特征和发育特点。结果表明:DT受精卵在水温(25±1)℃的条件下,整个胚胎发育过程约...对杂交三倍体泥鳅Misgurnus anguillicaudatus(2n♀×4n♂,DT)和二倍体泥鳅(2n♀×2n♂,DD)的胚胎发育进行观察,详细记录了其胚胎发育的形态特征和发育特点。结果表明:DT受精卵在水温(25±1)℃的条件下,整个胚胎发育过程约需36 h 19 min;对照组DD受精卵在水温(25±1)℃的条件下,整个胚胎发育过程约需35 h 57 min;DT(DD)的胚胎发育包括卵裂期、囊胚期、原肠期、神经胚期、器官形成期和孵化出膜期6个时期,DT(DD)受精卵约40 min(40 min)后进入卵裂期,3 h 45 min(3 h 40min)后进入囊胚期,6 h 30 min(6 h 24 min)后进入原肠期,9 h 32 min(9 h 20 min)后进入神经胚期,15 h 45 min(15 h 30 min)后进入器官形成期,36 h 19 min(35 h 57 min)后出膜。研究表明,DT的胚胎发育时序及形态特征与DD基本相似,说明DT具有正常的胚胎发育过程,本研究可为杂交三倍体泥鳅苗种培育提供生物学依据。展开更多
文摘The narrow genetic base in potato (Solanum tuberosum L.) limits the progress in cultivar development.The rich diploid germplasm in the origin center of potato provide a unique resource for improvement of tetraploid potatoes.Seven newly developed diploid hybrids with 2n pollen production,all of which have S. phureja background,were developed and evaluated for their value in potato breeding.They were crossed as male parnets to six tetraploid Solanum tuberosum cultivars,and seeds in large quantity from eleven crosses were obtained.Main agronomic traits,such as tuber yield,tuber number,mean tuber weight,tuber shape,eye depth,skin smoothness,flesh color,and specific gravity,were measured for 4x 2x tetraploid progenies in seedling generation,and their parents as well.All of the diploid hybrids had some merit for specific traits and the DH39 was more promising;high specific gravity trait in some diploid hybrids was successfully introgressed into tetroploid progenies via 4x 2x crosses.These diploid hybrids have potential value in potato breeding.
文摘In 1988, we found strain 9003 from compositehybridization of indica and japonica. 9003 pos-sesses characteristics of twin seedlings withfrequency of 15-20% of the investigated popu-lation. The highest frequency was 45.68%.Afterwards, we discovered that some twinseedlings had variabilities in chromosome set.As to a pair of twin plants, it may be 2n-1n,2n-3n, 3n-3n or 1n-1n. The changes in chro-mosome set also occurred in the plants devel-oped from mono-embryo seeds. All of thesevariants nearly account for 1% in our con-trolled experiment. We named the triploidplants SAR-3 and found that SAR-3 could be aresource of diploid true breeding hybrid rice.
基金supported by the Guangdong Provincial Key Project of Natural Science Foundation, China (Grant No. 021037)Guangdong Province Natural Science Foundation, China (Grant No. 7301008)+1 种基金South China Agricultural University President Foundation, China (Grant No. 2007K036)The Confocal Laser Scanning Microscope was provided by the Testing Center of South China Agricultural University, Guangzhou, China
文摘As maternal parents, diploid （L202-2x） and autotetraploid （L202-4x） of Oryza sativa cv. L2O2 were crossed with O. officinalis. Embryo development and fertilization in these two crosses were comparatively studied. There were no mature hybrid seeds obtained because all the hybridized spikelets died 30 days after pollination. The main reasons for no seed set were abnormal fertilization and development of the embryos and endosperms in the interspecific hybrids. There were doublefertilization, egg cell single-fertilization and non-fertilization in these crosses. Although 59.45% and 54.87% of hybrid embryos produced in the crosses of L202-2x/O. officinalis and L202-4x/O. officinalis, respectively, hybrid embryos ceased to develop or degenerated and plenty of free endosperm nuclei were in disaggregating state without developing cellular endosperms three days after pollination. Besides, some embryological differences in these two crosses were found, that is, the rate of double-fertilization and total rate of doubleand single-fertilization in L202-2x/O. officinalis were higher than those in L202-4x/O. officinalis. The embryo and endosperm of hybrids developed more slowly, and embryos and free endosperm nuclei were more severely degenerated in L202-4x/O. officinalis than in L202-2x/O. officinalis. Five days after pollination, a few of embryos in L202-2x/O. officinalis developed into pear-shaped ones, however, embryos in L202-4x/O. officinalis were all degenerated. Therefore, it is more difficult to obtain interspecific hybrids by wide crosses between autotetraploid of O. sativa and O. officinalis.
文摘对杂交三倍体泥鳅Misgurnus anguillicaudatus(2n♀×4n♂,DT)和二倍体泥鳅(2n♀×2n♂,DD)的胚胎发育进行观察,详细记录了其胚胎发育的形态特征和发育特点。结果表明:DT受精卵在水温(25±1)℃的条件下,整个胚胎发育过程约需36 h 19 min;对照组DD受精卵在水温(25±1)℃的条件下,整个胚胎发育过程约需35 h 57 min;DT(DD)的胚胎发育包括卵裂期、囊胚期、原肠期、神经胚期、器官形成期和孵化出膜期6个时期,DT(DD)受精卵约40 min(40 min)后进入卵裂期,3 h 45 min(3 h 40min)后进入囊胚期,6 h 30 min(6 h 24 min)后进入原肠期,9 h 32 min(9 h 20 min)后进入神经胚期,15 h 45 min(15 h 30 min)后进入器官形成期,36 h 19 min(35 h 57 min)后出膜。研究表明,DT的胚胎发育时序及形态特征与DD基本相似,说明DT具有正常的胚胎发育过程,本研究可为杂交三倍体泥鳅苗种培育提供生物学依据。
