四倍体高粱与约翰逊草间的亲缘关系分析

本研究以四倍体高粱与约翰逊草为材料,利用SSR分子标记和细胞遗传学方法分析了高粱与约翰逊草间的亲缘关系,SSR分析结果表明,高粱与约翰逊草的遗传背景差异较大,SSR差异位点和相似位点在连锁群上的分布具不平衡性;按照差异引物出现频率高低,将连锁群分为两类：高度差异区和低度差异区。细胞学分析结果表明：（1）双亲及杂交种都是不规则的四倍体遗传群体。（2）花粉母细胞减数分裂中期I,双亲及杂交种染色体配对以二价体和四价体为主,杂交种平均每个细胞二价体数为17．00,四倍体高粱为15．23、约翰逊草为15．83,四价体数分别为0．95,2．15和1．60个。但杂交种减数分裂过程中也出现一定数量的单价体,减数分裂会形成一定比例的非整倍配子。SSR检测结果与细胞学分析结果具有一致性,约翰逊草与高粱的染色体组间存在一定程度的同源性。二者杂交不能形成稳定遗传的双二倍体。     

高粱-苏丹草杂交种产草量与品质性状的回归分析

通过对7个高粱-苏丹草杂交种产草量与品质性状的相关和回归分析,结果表明：前一茬株高与后一茬产草量呈显著负相关,刈割3次的产草量间呈显著正相关,且均与总产草量呈极显著正相关;粗蛋白质与粗纤维含量呈显著负相关。粗脂肪与粗灰分含量呈显著正相关;产草量高低与品质性状无显著相关关系。通径分析结果表明：第1茬分蘖及3次产草量与总产量的直接通径系数都为正值,其中第2次刈割的产草量的直接通径系数最大,为0．5334^**。总产草量依各产草量性状的最优回归方程为：y^=-0．0522 0．0096x9 1．0006x13 1．0002x14 0．9989x15。     

同源四倍体荞麦的细胞遗传学研究

-V认为,人工诱变的同源四倍体禾谷类作物因减数分裂不规则性所产生的不育配子比例高,导致 结实率下降,是影响产鼠的主要原因。本文对同源四倍体荞麦和普通二倍体荞麦的外部形态、减数分 裂、花粉育性进行比较后认为,对不同作物的同源四倍体应作具体分析,就荞麦而言,当然也包括同源四 倍体荞麦,其结实率极低（最高为巧％）的主要原因,不是因为减数分裂不规则性所产生的不育配子比例 高,而是由于荞麦自身花器结构和外界条件所决定。同源四倍体荞麦的结实率与普通二倍体荞麦的结 实率无明显差异,增产的主要原因是由于千粒重的显著增加。     

同源四倍体荞麦的细胞遗传学研究

一般认为,人工诱变的同源四倍体禾谷类作物因减数分裂不规则性所产生的不育配子比例高,导致结实率下降,是影响产量的主要原因。本文对同源四倍体荞麦和普通二倍体荞麦的外部形态、减数分裂、花粉育性进行比较后认为,对不同作物的同源四倍体应作具体分析,就荞麦而言,当然也包括同源四倍体荞麦,其结实率极低(最高为15％)的主要原因,不是因为减数分裂不规则性所产生的不育配子比例高,而是由于荞麦自身花器结构和外界条件所决定。同源四倍体荞麦的结实率与普通二倍体荞麦的结实率无明显差异,增产的主要原因是由于千粒重的显著增加。     

高粱和苏丹草酯酶同工酶分析

采用聚丙烯酰胺凝胶电（PAGE）分析了6个高粱和4个苏丹草的酯酶同工酶差异,并通过聚类分析方法对10个品种的种质关系进行分层聚类。结果表明酯酶同工酶谱可以作为鉴别苏丹草和高粱的有效生化标记。     

四倍体稗草的组织培养与快速繁殖

以筛选得到的四倍体稗草成熟胚作为外植体,进行了组织培养与快速繁殖技术的研究。结果表明:最佳外植体消毒方式为70%乙醇浸泡30 s+0.1%(w/v)的升汞消毒15 min。最佳诱导培养基为MS盐、DL维生素+2.5 mg/L 2,4-D+300 mg/L谷氨酰胺+500 mg/L脯氨酸+3%麦芽糖。将愈伤组织转入分化培养基(MS+50 mg/L肌醇+1.0 mg/L 6-BA+0.2 mg/L KT+0.5 mg/L NAA+0.25 mg/L IAA+3%麦芽糖)上,培养20 d后超过70%的愈伤组织分化成苗。将3-5 cm长的分化苗转入1/2 MS生根培养基进行生根培养。炼苗后,移入营养土与珍珠岩(2∶1)的基质中,移栽成活率高达90%以上。该体系的建立为稗草抗除草剂基因的功能验证提供了前提条件。     

赖草属植物的遗传学研究与利用

赖草属植物具有广泛的适应性和丰富的抗逆性,作为麦类作物的重要基因资源愈来愈受到人们的重视。介绍了赖草属植物的种类及分布,分析了赖草属植物的优良特性及潜在利用价值,探讨了赖草属植物的核型、染色体带型及分子细胞遗传学研究,重点论述了赖草属植物在小麦遗传改良中的应用．阐明挖掘利用小麦近缘野生植物是未来小麦品种改良的有效途径。     

11个四倍体赖草属物种的核型研究

对11个四倍体赖草属Leymus Hochst.物种的核型进行了研究,核型公式如下：沙生赖草L. arenarius (L.) Hochst., 2n=4x=28=18m+4sm+6st (4sat); 密穗赖草L. condensatus (J. Presl) A. Lve, 2n=4x=28=22m+4sm (2sat)+2st (2sat); 新生赖草L. innovatus (Beal) Pilg., 2n=4x=28=24m (4sat) +4sm (2sat);多枝赖草L. multicau     

南荻同源四倍体的研究

南荻变种“突节荻”的幼穗、下胚轴产生的带绿芽点愈伤组织,置于０．０５％秋水仙碱的ＭＳ无激素培养基上处理２４－４８ｈ,经培养而诱变成交异试管苗。细胞学鉴定确定其染色体数目为２ｎ＝４ｘ＝７６（ｘ＝１９）,花粉粒和气孔保卫细胞均增大,核仁数目增多。田间种植和测定,获得南荻同源四倍体新品系。该品系表现出生长势强,植株高大,茎粗、茎壁厚、节间长,产量高,而且纤维长,长宽比值大,是生产上能直接利用的一种优质高产的造纸新资源     

Microsatellite Analysis of Genetic Variation and Population Genetic Differentiation in Autotetraploid and Diploid Rice

Genetic diversity and population genetic structure of autotetraploid and diploid populations of rice collected from Chengdu Institute of Biology, Chinese Academy of Sciences, were studied based on 36 microsatellite loci. Among 50 varieties, a moderate to high level of genetic diversity was observed at the population level, with the number of alleles per locus (A _e) ranging from 2 to 6 (mean 3.028) and polymorphism information content ranging from 0.04 to 0.76 (mean 0.366). The expected heterozygosity (H _e) varied from 0.04 to 0.76 (mean 0.370) and Shannon’s index (I) from 0.098 to 1.613 (mean 0.649). The autotetraploid populations showed slightly higher levels of A _e, H _e, and I than the diploid populations. Rare alleles were observed at most of the simple sequence repeat loci in one or more of the 50 accessions, and a core fingerprint database of the autotetraploid and diploid rice was constructed. The F-statistics showed genetic variability mainly among autotetraploid populations rather than diploid populations (F _st = 0.066). Cluster analysis of the 50 accessions showed four major groups. Group I contained all of the autotetraploid and diploid indica maintainer lines and an autotetraploid and its original diploid indica male sterile lines. Group II contained only the original IR accessions. Group III was more diverse than either Group II or Group IV, comprising both autotetraploid and diploid indica restoring lines. Group IV included a japonica cluster of the autotetraploid and diploid rices. Furthermore, genetic differences at the single-locus and two-locus levels, as well as components due to allelic and gametic differentiation, were revealed between autotetraploid and diploid varieties. This analysis indicated that the gene pools of diploid and autotetraploid rice were somewhat dissimilar, as variation exists that distinguishes autotetraploid from diploid rices. Using this variation, we can breed new autotetraploid varieties with some important agricultural characters that were not found in the original diploid rice varieties.     

Selection of Primary Trisomics from Anther Culture of Autotetraploid Rice (Oryza sativa L.)

The hybrids from different generations of autotetraploid rice (Oryza sativa L. ) and the original autotetraploid rice (indica and japonica) were used for anther culture, and the pollen-plantlets from them were induced. Due to the significant difference on phenotype among the trisomics and between trisomics and diploid, 15 lines of 4390 H1 induced plants were selected for chromosome study. Their PMC meiosis were observed. The results showed that the chromosomes from these plants consisted of 2n, 4n and aneuploids, and their ratios were 88.00%, 5.53% and 6.47% respectively. 272 trisomics from 284 aneuploids were identified, which acounted for 6.20% of all the pollen-plants. According to the special characters from the whole set of trisomics, they were classified as 9 types. The 9124- 7 trisomics were designated as triplo-8 by the pachytene analysis. Sowing the seeds of triplo8, the transmission rate of extra chromosome was calculated at the seedling stage of H2. The rate of trisomic was 34.11% of all plants, the agronomic characters were similar to the H1 parent plants.     

采用秋水仙碱创制优质、抗热同源四倍体不结球白菜

以不同浓度秋水仙素处理二倍体不结球白菜(Brassica campestrisssp.chinensisM ak ino)子叶生长点,对变异株进行了形态解剖学、农艺学、细胞学及营养品质鉴定。结果表明:0.1 mol/L秋水仙素处理6次的效果最佳。与二倍体相比,四倍体植株、气孔、花器官均表现巨大性;气孔密度、结实率显著降低;四倍体白菜蛋白质、可溶性糖和维生素C含量比二倍体分别增加15.69%、71.25%和22.18%;夏季高温条件下四倍体表现出良好的丰产性和抗热性。     

高粱叶片磷酸烯醇式丙酮酸羧化酶疏水微区的荧光研究

应用疏水荧光探针──ＡＮＳ在不同浓度的变构效应剂存在时进行荧光滴定．磷酸烯醇式丙酮酸羧化酶分子中疏水微区的微环境能被效应剂或底物诱导产生变构,不同的变构效应剂所诱发的构象态是不一致的。这进一步证明了高粱叶片磷酸烯醇式丙酮酸羧化酶在溶液中的多构象态。     

Microbial Succession During “Kunun Zaki” Production with Sorghum (Sorghum bicolor) Grains

Microorganisms associated with the production of kunun zaki using sorghum grains were isolated and characterized. They consisted mainly of lactic acid bacteria, Lactobacillus plantarum, Leuconostoc mesenteroides, Corynebacterium, Lactococcus lactis, Pediococcus cerevisiaeand yeast Saccharomyces cerevisiae. The organisms occurred in various numbers at different stages of production but persisted to the end of the production process. The growth of lactic acid bacteria brought about a gradual decrease of pH of the steeping medium from 6.87 to 4.78 in the final product. Although it is clear that specific microorganisms are involved in the production process, the chances of contamination seem to be unavoidable, as the process is not standardized and the processing environment is unhygienic. There is lack of precautionary measures against contamination and crude household materials are used in processing. Since the use of local household materials cannot be avoided, it is suggested that good manufacturing practices at all stages of production and application of the hazard analysis critical control point (HACCP) concept be applied to reduce the level of contamination.     

High Throughput BAC DNA Isolation for Physical Map Construction of Sorghum (Sorghum bicolor)

With the aim of constructing a physical map of sorghum, we developed a rapid, high throughput approach for isolating BAC DNA suitable for restriction endonuclease digestion fingerprinting, PCR- based STS-content mapping, and BAC-end sequencing. The system utilizes a programmable 96 channel liquid handling system and associated accessories that permit bacterial cultivation and DNA isolation in 96-well plate format. This protocol details culture conditions that optimize bacterial growth in deep-well plates and criteria for BAC DNA isolation to obtain high yields of quality BAC DNA. The system is robust, accurate, and relatively cost-effective. The BAC DNA isolation system has been tested during efforts to construct a physical map of sorghum.     

根癌农杆菌介导的高粱遗传转化体系的研究

采用根癌农杆菌介导法将杀虫晶体蛋白基因cryIA(b)转入高粱胚性愈伤组织中,建立农杆菌转化高粱的遗传转化体系,获得70棵再生植株。经GUS及PCR检测,结果表明,cryIA(b)基因确实转移到高粱恢复系0-30中,报告基因GUS在再生植株中也得到表达。转化植株的抗病性鉴定正在进行中。     

甜高梁离体再生体系的建立和组织结构变化的观察

以甜高粱成熟种子为外植体,调节不同生长调节物质配比建立甜高梁离体再生体系。结果表明在MS＋2．5mg．L^-12,4．D＋0．3mg·L^-1KT培养基上愈伤组织的诱导率可达77．26％;比较不同浓度6-BA或TDZ与NAA配合诱导愈伤组织分化和苗形成的情况,TDZ的作用优于6-BA。观察培养组织的结构变化发现,甜高粱离体再生过程中除了体细胞胚发生途径之外,还伴随有器官发生途径。