甘蓝杂种致死材料的鉴定与遗传分析

杂种致死是一种生殖隔离类型,致死材料的鉴定及遗传分析不仅有助于了解杂种致死的遗传机制,还可以为致死基因的定位和克隆奠定基础。利用已知携带杂种致死基因的甘蓝自交系09-211、09-222、10-260和其他自交系配制的杂交组合为试材,鉴定携带致死基因的新材料,并对甘蓝杂种致死性状进行了遗传分析。结果表明:11-204和11-176是2个新的甘蓝致死材料;11-176与09-222及10-260具有遗传等效性,而11-204与09-211具有遗传等效性;甘蓝杂种致死性状是由2个显性基因互补控制的,其中1个致死基因来自09-211或11-204,另1个致死基因来自09-222或10-260或11-176,其遗传模式符合Dobzhansky-Muller(DM)模式。     

大豆吡哆醇生物合成蛋白基因(PDX)的电子克隆和进化分析

电子克隆(In silicocloning)是随着基因组计划和EST计划实施而发展起来的利用生物信息学手段进行基因克隆的新方法。根据物种间同源基因相对保守的特点,以拟南芥(Arabidopsis thaliana)吡哆醇生物合成蛋白cDNA序列为信息探针,对大豆(Glycine max)EST数据库进行同源搜索和序列拼接,获得了1 280 bp长的大豆吡哆醇生物合成蛋白的基因序列(GenBank登陆号为DQ139265)。经过RT-PCR扩增、基因组PCR扩增、分子克隆和序列分析验证,结果表明与电子克隆序列完全一致。该基因具有完整的开放阅读框架(ORF,20~955 bp),编码311个氨基酸。通过与水稻、日本百脉根、烟草、截形苜蓿等物种的吡哆醇生物合成蛋白序列比对,发现该基因具有高度的保守性。表明根据物种间同源基因序列,对跨物种间EST数据库进行同源检索、筛选、拼接,是克隆基因的有效途径。     

The global adaptation of bread wheat at high latitudes

Spring sown bread wheat is grown at high latitudes in Europe, Asia and North America. However, it is not clear what the associations are among environments, particularly in Asia and North America, and whether or not cultivars developed in one region may adapt in another. A yield trial comprised of cultivars developed in northern Kazakhstan, western Siberia, the Canadian Prairies, northern USA, northeastern China and broadly adapted genotypes bred by CIMMYT in Mexico was planted in all the above mentioned environments in 2002–2004. In general, cultivars performed best within the regions they were developed. However, cultivars developed in northern Kazakhstan/western Siberia were the most broadly adapted at high latitudes; they were not significantly different for grain yield from the locally developed cultivars in both China and Canada. Stronger photoperiod response, greater plant height and larger seed weight appeared to be key adaptive features of these materials. At lower latitudes, the Kazakh/Siberian cultivars were significantly lower yielding than all other materials. When low latitude Mexican sites were removed from the analysis, the Chinese locations tended to associate, whereas most Canadian and Kazak/Siberian locations were negatively associated with those from China. SSR analysis of the cultivars from each region split the materials into two general groups, one based on North American cultivars and one comprised of Kazakh/Siberian and Chinese cultivars. Lines developed in Mexico were spread across these two groupings. Evidence suggests that considerable scope exists to improve bread wheat adaptation at high latitudes globally through intercrossing materials originating from Asia and North America.     

不同水(陆)稻品种(系)干旱胁迫效应分析评价

为了扩大水稻抗旱资源的应用,提高水稻抗旱育种效率,对来自17个不同国家105份水(陆)稻品种(系)进行干旱胁迫效应评价。采用了同异分析法,在干旱胁迫下,株高、单株有效穗、穗长、每穗实粒数、每穗总粒数、结实率、千粒重、单株谷重8项农艺及经济性状,进行了综合评价分析。结果表明:105份水(陆)稻品种(系),分析评语"差"的有60个品种,占57.1%;"一般"的评语共有22个品种,占21%;"较好"和"好"的评语各有10个品种,占9.5%;"优良"的只有4个品种,占3.8%,分别为IR77298-14-1-2-13、IR77298-5-6-18、CACHO PRETO、IR77298-5-6-11,均为籼稻品种。由此得出,籼稻品种抗旱性明显高于粳稻品种,抗旱同异评语的级别与每穗实粒数、结实率、单株谷重3个性状密切相关。     

用改进的高盐低pH法分离和纯化棉花叶绿体及叶绿体DNA

报道了用改进的高盐低ｐＨ法分离和纯化棉花叶绿体及叶绿体ＤＮＡ的实验过程，即先在高盐（离子强度）介质下，通过ｐＨ值变换，多次洗涤的方法去除叶绿体表面的静电附着杂质，得到纯净的叶绿体；然后氯仿抽提纯化ＤＮＡ；最后采用界面针挑法得到高纯度的ｃｐＤＮＡ。实验过程中针对棉花的特点，采用ＰＶＰ排除棉酚和丹宁的干扰，用ＤＩＥＣＡ抑制酚氧化酶活性，并对实验细节作了较大改进。得到的ＤＮＡ可满足酶切、ＰＣＲ等分子生物学分析。     

Resistance to the Barley Yellow Mosaic Virus Complex — Differential Genotypic Reactions and Genetics of BaMMV-Resistance of Barley (Hordeum vulgare L.)

Barley yellow mosaic disease is caused by several viruses, i.e. barley yellow mosaic virus (BaYMV), barley mild mosaic virus (BaMMV) and BaYMV-2. The reaction of different barley germplasms to the barley mosaic viruses was studied in field and greenhouse experiments. The results show a complex situation; some varieties are resistant to all the viruses, while others are resistant to one or two of them only. Crosses between different barley germplasms were earned out in order to test whether genetic diversity of resistance against mosaic viruses does exist, particularly, BaMMV. A total of 45 foreign barley varieties were crossed to German cultivars carrying the resistance gene ym4. In F₂ of 27 crosses, no segregation could be detected, leading to the conclusion that the resistance genes of the foreign parents are allelic with ym4 e.g. Ym1 (‘Mokusekko 3’) and Ym2 (‘Mihori Hadaka 3’). A total of 18 crosses segregated in F₂ indicating that foreign parents, like ‘Chikurin Ibaraki 1’, ‘Iwate Omugi 1’, and “Anson Barley”, carry resistance genes different from the gene of German cultivars, e.g. ‘Asorbia’ or ‘Franka’. By means of statistical evaluation (Chi²-test), the observed segregation ratios were analyzed in order to obtain significant information on the heredity of resistance. All the resistance genes described here as being different from the gene ym4, act recessively. Most of the exotic varieties seem to carry only one resistance gene. In a few cases, more than one gene may be present.     

棉花烂铃病流行趋势超长期预报模型及其应用研究

本文对ＧＭ（１，１）模型参数估计方法进行了改进和简化，据此组建了苏北沿海棉区棉花烂铃病流行趋势超长期预报模型，经１９８０～１９８９年回报和１９９０～１９９５年预报，棉花烂铃病流行轻、重发生的符合率达１００％；１９９６～２０００年预报结果为１９９８年和２０００年为重发生，其余３ａ为轻发生。这将为棉花烂铃病的研究和防治规划提供科学决策依据，也为ＧＭ（１，１）模型能在基层病虫测报站推广应用创造了条件。     

Integration of AFLP markers into a linkage map of sugar beet (Beta vulgaris L.)

The AFLP (amplified fragment length polymorphism) technique has been applied in establishing an extended linkage map of sugar beet. A total of 120 AFLPs were integrated into an existing linkage map based on RFLP markers. Four primer combinations yielded between 19 and 40 polymorphic bands in an F₂ population consisting of 94 plants. The AFLP loci were evenly distributed over the nine linkage groups, with the exception of linkage group V where the number of AFLPs was significantly low. The AFLPs were found to be reproducible even against the background of different combinations of Taq DNA polymerases and buffers. However, the quantity of higher molecular weight fragments (>400 bp) was reduced when using plant DNA of poor quality as a template. The results of these experiments are discussed, together with possible applications of AFLPs in sugar beet breeding.     

魔芋试管微球茎成熟度对其储藏及萌发率的影响

种子在母体植株上的干燥过程是种子完成从发育到萌发的一个重要转换点。魔芋组织培养中诱导试管微球茎过程中，在色泽上有1个明显的变化过程。本实验将这个过程分为3个阶段，对不同采收时期的微球茎进行储藏及萌发研究，结果表明，不同采收期的微球茎，储藏后的萌发率具有较大的差异，而且这种差异与魔芋种具有较大的相关性，这种差异与其保水性能有关。同时对试管微球茎收获度对储藏后萌发率影响的机制进行了初步的探讨。     

self-(in)compatibility almond genotypes: A review

To compile self-(in)compatibility almond genotypes, a review of 133 commercial cultivars of wide geographical origin was made. The information gathered from own and mainly published work will be useful for both grower's cultivar choice when planting and for breeder's cross design when planning. The almond S genotypes compiled were identified using five different methods: biological (pollination tests in the field and in the laboratory) and molecular (RNases, PCR and sequencing). In most cases, genotypes were assigned after combining more than one technique. Cultivars were classified into three categories: self-incompatible (99), self-compatible (16) and doubtful self-incompatible (18). The database is divided in 9 fields (name, origin, parentage, obtention year (crossing, selection or release), S genotype, technique used, reference, consensus genotype, and cross incompatibility group). A study of the 27 S alleles already identified and their geographical distribution within the cultivated almond is also presented. The study was divided into cultivars of known and unknown parentage and the distribution of S alleles frequencies was uneven among the 133 cultivars. S allele frequencies are related to geographical origin. Some alleles (S ₁, S ₅, S ₇ and S ₈) are more frequently observed than the others among cultivars of both known and unknown parentage. In the cultivated almond, the S f allele is only found in the Puglia region, Italy. The S _f frequency is three times higher in cultivars released from breeding programmes than in cultivars selected by growers. From the 351 resulting possible genotypes by combination of the 27 S alleles identified only 20 CIG (0-XIX) have been established, which represents a small fraction of the whole genetic diversity of this polymorphic gene in almond.