矮小鸡在高原地区生长速度研究

通过对矮小鸡配套系在高原地区的孵化和饲养试验,测定不同周龄的生长发育,并与在高原适应性较强的藏鸡进行比较.研究结果表明,矮小鸡配套系在高原地区的适应性比较强.     

对新引进IR不育系的观察与评价

从印度引进１５个ＩＲＲＩ育成的不育系和相应的保持系,在中国水稻研究所试验基地（富阳）观测其育性及主要农艺性状,并初步配组测产。结果表明,１０个不育系育性稳定,符合标准;ＩＲ５８０２５Ａ与明恢６３、Ｔ９０１０配组,其杂种产量与汕优６３相仿,但生育期较短、米质较优。     

四芯网线解决图书馆网络问题

探究了百兆网线的工作原理,根据原理提出了用同一根双绞线接两个水晶头当作两根四芯网线使用的方法,并用它解决了图书馆局域网的实际问题。     

西瓜核型雄性不育两用系POD同工酶研究

用PAGE(聚丙烯酰胺凝胶)电泳技术,研究了西瓜核型雄性不育两用系不同器官的POD(过氧化物酶)同工酶酶谱差异。试验结果表明,不育株与可育株主要差异在雄花蕾,表现为不育株较可育株多2条活性强的酶带;其他器官差异小,仅表现为酶谱带强弱不同。并对POD同工酶与雄性不育性的相关性进行了研究。     

盐胁迫对小麦代换系幼苗叶片保护酶活性影响及染色体效应

为研究盐胁迫对小麦代换系酶活性的影响,以中国春-Synthetic 6x 染色体代换系及其亲本为材料,通过测定在盐处理条件下幼苗抗氧化酶SOD、POD活性和丙二醛（ MDA）含量变化,并对其相关耐盐特性的基因进行染色体定位。采用霍格兰营养液水培法,设置对照（0 mmol/L NaCl）和盐处理（150 mmol/L NaCl）,在幼苗两叶一心时进行处理,四叶一心时取样,分别测定对照和盐处理条件下幼苗的SOD和POD活性以及MDA含量。在盐胁迫条件下,小麦代换系幼苗SOD和POD活性显著升高,丙二醛含量降低。其中,1A、5A、6A、1B、5B、6B、7B和5D代换系的SOD活性显著或极显著高于母本中国春,2A、1B、2B、3B、5B、6B、5D和6D代换系的相对SOD 活性显著或极显著高于母本中国春;3A、4A、5A、6A、7A、6B和7D代换系的POD 活性显著或极显著高于中国春,4A、5A、6B、1D和7D 代换系的相对POD活性显著或极显著高于中国春。由于保护酶的作用,在盐胁迫条件下,多数代换系MDA含量明显减少,2A、3A、4A、6A、1B、3B、4B、5B、6B、7B、1D、5D和7D代换系的MDA含量显著或极显著低于母本中国春,2A、6A、6B、1D和2D代换系的相对MDA含量显著或极显著低于母本中国春。 Synthetic 6x 的1B、5B、6B 和5D 染色体上可能存在诱导幼苗SOD活性增强的基因,4A、5A、6B和7D染色体上可能存在诱导幼苗POD 活性增强的基因,抑制幼苗MDA含量增高的基因可能存在于2A、6A、6B和1D染色体上。     

Characterization of segregation distortion on chromosome 3 induced in wide hybridization between indica and japonica type rice varieties

We previously surveyed chromosomal regions showing segregation distortion of RFLP markers in the F₂ population from the cross between a japonica type variety ‘Nipponbare’ and an indica type variety ‘Milyang23’, and showed that the most skewed segregation appeared on the short arm of chromosome 3. By comparison with the marker loci where distortion factors were previously identified, this region was assumed to be a gametophytic selection-2 (ga2) gene region. To evaluate this region, two near isogenic lines (NILs) were developed. One NIL had the ‘Nipponbare’ segment of this region on the genetic background of ‘Milyang23’ (NIL9-23), and the other NIL had the ‘Milyang23’ segment on the genetic background of ‘Nipponbare’ (NIL33-18). NIL9-23 and ‘Milyang23’, NIL33-18 and ‘Nipponbare’, and ‘Nipponbare’ and ‘Milyang23’ were respectively crossed to produce F₁ and F₂ populations. The F₁ plants of NIL9-23 × ‘Milyang23’ and NIL33-18 × ‘Nipponbare’ showed high seed fertility and the same pollen fertility as their parental cultivars, indicating that ga2 does not reduce seed and pollen fertility. Segregation ratio of a molecular marker on the ga2 region in the three F₂ populations was investigated to clarify whether segregation distortion occurred on the different genetic backgrounds. Segregation distortion of the ga2 region appeared in the both F₂ populations from the NIL9-23 and ‘Milyang23’ cross (background was ‘Milyang23’ homozygote) and the ‘Nipponbare’ and ‘Milyang23’ cross (background was heterozygote), but did notin the F₂ population from the NIL33-18 and ‘Nipponbare’ cross (background was ‘Nipponbare’ homozygote). This result indicates that ga2 interacts with a ‘Milyang23’ allele(s) on the different chromosomal region(s) to cause skewed segregation of the ga2 region. In addition, segregation ratio was the same between the F₂ populations from NIL9-23 × ‘Milyang23’ and ‘Nipponbare’ × ‘Milyang23’ crosses, suggesting that the both genotypes, ‘Milyang23’ homozygote and heterozygote, of gene(s) located on the different chromosomal region(s) have the same effect on the segregation distortion. This revised version was published online in July 2006 with corrections to the Cover Date.     

Two genes and linked RAPD markers involved in resistance to Fusarium oxysporum f. sp. Ciceris race 0 in chickpea

The inheritance of resistance to fusarium wilt race 0 of chickpea and linked random amplified polymorphic DNA (RAPD) markers were studied in two F₆:₇ recombinant inbred line (RIL) populations. These RILs were developed from the crosses CA2156 × JG62 (susceptible × resistant) and CA2139 × JG62 (resistant × resistant), and were sown in a field infected with fusarium wilt race 0 in Beja (Tunisia) over 2 years. A1:1 resistant to susceptible ratio was found in the RIL population from the CA2156 × JG62 cross, indicating that a single gene with two alleles controlled resistance. In the second RIL population (CA2139 × JG62) a 3:1 resistant to susceptible ratio indicated that two genes were present and that either gene was sufficient to confer resistance. Linkage analysis showed a RAPD marker, OPJ20600, linked to resistance in both RIL populations, which is present in the resistant parent JG62.     

Wide mapping of a T-DNA insertion site in oilseed rape using bulk segregant analysis and comparative mapping

Doubled haploid oilseed rape lines segregating for a transgene inducing herbicide resistance (bar gene) were investigated for the wide mapping of the T-DNA insertion site. Bulk segregant analysis using presence/absence and intensity polymorphisms between the bulks, as well as comparative mapping with a linkage group deriving from another cross, led to the identification of 11 random amplified polymorphic DNA (RAPD) markers tightly or loosely linked to the bar gene. Ten RAPD loci out of 11 were located on the same side of the bar locus, strongly suggesting that the T-DNA integrated in a telomeric or subtelomeric position. The eleventh RAPD marker exhibited a strong segregation distortion, which could be the result of a heteroduplex formation. Comparison of the linkage groups obtained from the two crosses showed different recombination rates between markers, possibly reflecting differences in parental genetic backgrounds. Consequences and potential applications in transgene dispersal safety assessment studies are discussed.     

Potential use of doubled haploid lines for the screening of resistance to yellow rust (Puccinia striiformis) in hexaploid wheat

Doubled haploid lines derived from anther culture of two Iranian spring wheat genotypes‘Ghods’susceptible and‘9106’resistant to yellow rust in Iranian field conditions, and their F₁ hybrids were used in this study. Seedlings of 36 doubled haploid lines, selected out of 96 according to their agronomic traits and the two parental genotypes were inoculated with eight races of yellow rust. The parental genotypes (‘Ghods’and‘9106’) were segregating for some of the races but their doubled haploid lines were either resistant or susceptible to them.‘Ghods’was susceptible to three of the races studied but three doubled haploid lines derived from it were resistant to them. Five selected doubled haploids from the‘9106’genotype and six from F₁ hybrid plants were resistant to all eight races tested. After further investigations in Iranian field conditions it was found that some of these lines can be used as donor genotypes for resistance to yellow rust in wheat breeding programmes. Use of these genotypes should be possible if the French yellow rust races used for selection also represent the dominant races in Iran. It can be concluded that anther culture provides an efficient method for fixing genes of resistance to yellow rust and desirable doubled haploids from F₁ plants can be derived.