小鼠四倍体囊胚凋亡及凋亡基因的表达

为了更全面的对四倍体胚胎的发育能力进行评估,本研究利用原位末端标记(TUNEL)法检测了电融合生产的小鼠四倍体囊胚细胞凋亡情况,同时用实时定量PCR方法检测了促凋亡基因Bax和抑凋亡基因Bcl-2在四倍体囊胚中的表达。结果显示:四倍体与体外二倍体胚胎发育到囊胚的比率没有显著差别(P0.05);四倍体囊胚无论是内细胞团细胞数、滋养层细胞数还是内细胞团/总细胞数比率都显著低于体内与体外二倍体囊胚(P0.05);四倍体囊胚细胞凋亡指数显著高于体内与体外二倍体囊胚细胞凋亡指数(P0.05);促凋亡基因Bax在四倍体囊胚中的表达显著高于体内与体外二倍体囊胚中的表达(P0.05),而抑凋亡基因Bcl-2在四倍体囊胚中的表达同体内与体外二倍体囊胚中的表达没有显著差异(P0.05)。因此,四倍体囊胚质量比体内与体外二倍体囊胚质量都差,这可能是四倍体胚胎不能发育到足月的原因之一。     

利用7个置换系和渐渗系的双列杂交研究海陆杂种的数量性状遗传

对7个置换系和渐渗系与陆地棉遗传标准系TM 1的重要农艺性状进行了系统遗传分析。利用加性显性加性×加性上位性及其与环境互作模型(ADAA),分析了8个杂交亲本和28个F1主要农艺性状的2年资料,估算了各项遗传方差分量。结果表明,产量性状主要受加性效应和显性效应共同控制,其中衣分和衣指加性方差的比率较高,分别为33.0%和42.2%,单株铃数以显性效应为主。纤维长度和麦克隆值存在显著的加性×加性上位性效应,比强度由加性和显性效应共同控制。主要产量和品质性状的狭义和广义遗传率均达到极显著水平。     

氨磺灵和秋水仙素诱导橡胶草四倍体效果的比较研究

为探讨不同诱变剂对橡胶草四倍体的诱导效果,以橡胶草幼芽为材料,采用浸芽法,比较分析氨磺灵和秋水仙素2种诱变剂不同浓度和处理时间对橡胶草多倍体的诱导效果及多倍体橡胶草的形态特征变化。结果表明：氨磺灵处理橡胶草的成苗率(60%~75%)和最高诱变率(14.08%)均高于秋水仙素处理（0~59%和5.56%）,其嵌合体率(27.27%)低于秋水仙素处理(75.00%),其中0.04 mmol/L氨磺灵处理 30 min,成苗率为71.00%,变异率14.08%,为最佳诱变条件。可见,氨磺灵比秋水仙素更适合用于橡胶草多倍体诱导。诱导后获得的四倍体橡胶草叶片厚度、气孔大小、花和种子大小均显著大于野生型二倍体植株,气孔密度则显著低于野生型植株,这些形态特征可辅助多倍体橡胶草快速筛选和鉴定。本研究初步探明了2种诱变剂对橡胶草染色体加倍的诱导效果,为今后橡胶草多倍体育种提供理论依据和技术支持。     

四倍体鲜食酸枣新品种‘珠光’

酸枣‘珠光’是采用田间愈伤途径免嵌合体纯化多倍体诱变方法,由‘邢台0604’酸枣经秋水仙素诱变获得的纯同源四倍体新品种。叶色浓绿,叶缘皱褶明显;果实大,近圆形,平均单果质量7.76 g;果肉较脆,酸甜,风味浓,鲜食品质优良;较抗缩果和裂果;早果,丰产;9月上中旬着色成熟。适宜在河北省献县、赞皇县、行唐县及生态条件类似区域栽培。     

Strontium accumulation in whole grain of Aegilops and Triticum species

Plant species differ in their ability to accumulate mineral elements. Differences also exist among genotypes, lines, and varieties within species. Strontium (Sr) enters the food chain primarily via plants, and wheat products are amongst the most important pathways by which Sr enters the human body. The aim of this study was to analyze the accumulation of Sr in whole grain of various Aegilops and Triticum species with different genomes (AA, BB, BBAA, BBAADD, and DD). During three experimental years plants were grown in temperate continental climate on a calcareous, gleyic chernozem soil. The results reveal that the studied species and genomes differed significantly in Sr accumulation in the grains. The average Sr concentration of the grains ranged, depending on the year of study and genotype, from 0.70 to 3.89 mg kg ⁻¹ DM. The grain of wild diploid Aegilops speltoides with BB genome contained significantly more Sr than all of the other analyzed genotypes. Grains of wild and cultivated tetraploid wheat genotypes had the lowest Sr concentration. The modern cultivated hexaploid wheat varieties displayed substantial variation in Sr concentration in the grains. The examined genotypes also differed significantly with respect to their mass of 1000 grains, which was the smallest in Aegilops speltoides . There was a significantly negative correlation between the average mass of a 1000 grains and concentration of Sr. The results show that even when the background concentration of Sr was relatively low, wheat genotypes accumulated it in the grains, although to a different extent. Therefore, selection of wheat genotypes which accumulate less Sr in the grain could contribute to improve food quality.     

转基因小麦中的转基因向它的近缘杂草转移的可能途径

通过测定杂交后代的基因的转移,研究草甘磷抗性基因从转基因小麦向它的近缘杂草转移的三条可能途径。理论上分析,通过有性杂交基因小麦通过如下三条途径转移它的抗性基因,１杂种自交,形成抗性分离的含有四倍体和五倍体的转基因混合群体;２Ｆ１与四倍体杂草自发杂交;３Ｆ１与六倍体转基因小麦杂交。研究证实了确定存在基因小麦 基因与它的近缘杂草转移的风险,但是由于Ｆ１自交不育,第一条途径基本上是不可能的,第二,第三条途径是基因转移的主要方式,它们的杂交后代是自交可育的,有可能成为抗性基因从转基因小麦转移到近缘杂草的桥梁,最终形成一种新的杂草,即所谓“超级杂草”。根据研究结果,建议采用生物技术创造多抗基因系以延长转基因品种的使用,采用管理措施以避免交杂发生,从而避免或减轻基因转移的风险。     

The inheritance and chromosomal location of a gene for long glume in durum wheat

Summary Several near-isogenic lines of durum wheat cv. LD222 have been developed. These include a near-isogenic line carrying gene P and designated P-LD222. The P gene from Triticum polonicum determines a long empty outer glume. The objective of this study was to determine the inheritance and chromosomal location of the P gene. To determine the inheritance, P-LD222 was crossed to two chlorina mutants and to a near-isogenic line for the purple culm trait, Pc-LD222. Linkage of the P gene with the mutated gene in chlorina mutant CDd6 indicated that the P gene was located on chromosome 7A. P-LD222 was also crossed with durum cultivar Langdon (LDN) and the LDN D genome substitution lines, LDN 7D(7A) and LDN 7D(7B). Segregation for the long glume trait in the F₂ of LDN/P-LD222 and LDN 7D(7B)/P-LD222 was normal (3:1) and indicated P gene was not on chromosome 7B. Significant deviation from a 3:1 in the F₂ of LDN 7D(7A)/P-LD222 confirmed the location of P on chromosome 7A, as indicated by the linkage analysis.     

Introgression of Cajanus platycarpus genome into cultivated pigeonpea, C. cajan

Summary Cajanus platycarpus, an incompatible wild species from the tertiary gene pool of pigeonpea (C. cajan (L.) Millspaugh), has many desirable characteristics for the improvement of cultivated varieties. To necessitate such transfers, embryo rescue techniques were used to obtain F₁ hybrids. The F₁ hybrids were treated with colchicine to obtain tetraploid hybrids, that were selfed to obtain F₂, F₃ and F₄ progenies. All of the hybrids and subsequent progenies had an intermediate morphology between the two parents. Backcrossing of the tetraploid hybrids with cultivated pigeonpea was not possible given embryo abortion, with smaller aborted embryos than those obtained in the F₀ parental cross.As a route of introgression, diploid F₁ hybrids were backcrossed with cultivated pigeonpea and BC₁ progeny obtained by in vitro culture of aborting embryos. BC₂ plants were obtained by normal, mature seed germination. Although embryo rescue techniques had to be used to obtain F₁ and BC₁ plants, it was possible to produce BC₂ and subsequent generations through direct mature seed. Every backcross to cultivated pigeonpea increased pollen fertility and the formation of mature seeds.Special project assistant till December, 2003.     

Variation of high-molecular-weight glutenin subunits amongst cultivars of Triticum turgidum L. from Portugal

Summary Variation in high-molecular-weight (HMW) glutenin subunit composition amongst 63 varieties of Triticum turgidum L. from Portugal was investigated using SDS-PAGE. A total of thirteen Glu-A1 and Glu-B1 alleles were identified, and three of them were found to be different from those previously described in the literature. A number of the tetraploid wheats examined contained subunits known to have a beneficial effect of the bread-making properties of T.aestivum. Camara, a tetraploid wheat cultivar carrying a 1D/1B chromosomal substitution, is proposed as a bridge for the transfer of Glu-D1 alleles and of other protein fractions controlled by the 1D chromosomes (Gli-D1 locus) from hexaploid to tetraploid wheat.     

四倍体刺槐大小孢子发生和雌雄配子体发育

为了积累四倍体刺槐生殖生物学资料和为四倍体刺槐遗传改良奠定基础,对四倍体刺槐的大小孢子发生与雌雄配子体发育进行了研究.结果表明:四倍体刺槐花药壁由孢原细胞分裂形成的初生壁细胞发育而来,中层较早解体,绒毡层发育属腺质绒毡层.小孢子母细胞减数分裂为同时型,多形成四面体型的四分体,成熟花粉为2细胞型;胚囊发育为蓼型,成熟胚珠为双珠被、厚珠心、弯生型胚珠,靠近合点端的大孢子为有功能大孢子,成熟胚囊为8核.