Could early gene flow have created similar allozyme-gene frequencies in cultivated and wild barley?

The possible role of early gene flow between wild and cultivated barley in their similar esterase gene frequencies was tested in a simulation study. The hypothetical population consisted of 99.9% wild forms possessing three alleles of an esterase gene and 0.01% domesticated forms possessing one of these esterase alleles. Various rates of inbreeding, selection coefficients against the wild form and shifting cultivation methods were tested for their effect on the establishment of the domesticated form and the esterase gene flow between the two barley types. Of these factors, inbreeding rates, in the range of 90–99%, had the smallest effect on the establishment of the domesticated form under primitive cultivation. Via gene flow, the esterase allelic frequency in the domesticated form could be similar to that of the wild form under 90% outcrossing in the domesticated form for 115–230 years, an unrealistic situation for barley which normally exhibits about 1% outcrossing. It seems, therefore, that the similar esterase allelic frequencies in wild and cultivated barley is only partly due to gene flow, and it is more plausibly accounted for by multiple domestications.     

中国近代陆地棉引种和驯化评述

鸦片战争后,纺纱业和织布业在中国的兴起引起棉花需求量增大,刺激了农民种棉的积极性。为了满足纺织业的需要,我国从晚清便开始了陆地棉的引种工作。张之洞率先从美国引回陆地棉品种,在湖北种植,尔后还有其他清政府官员也引进过种陆地棉品种,但由于缺乏科学引种知识导致失败。张之洞等人之后,张謇比较科学地引进并驯化陆地棉品种取得成功。在南京金陵大学美国专家的支持下,国民政府成立了植棉机构,筛选出适合中国实际的陆地棉棉品种,如爱字棉、斯字棉、德字棉等,使其成为当时主栽棉花品种,为中国近代棉花种植业贡献很大。     

阿拉善沙拐枣引种驯化栽培试验

通过10年(2001～2010)的驯化栽培,将具有高抗旱、耐风沙的野生灌木阿拉善沙拐枣从民勤沙区引种至兰州获得成功.试验结果表明:经过驯化栽培,该种植物在兰州地区人工栽培条件下,能够正常生长、结籽和成熟,从播种(移栽)出苗(萌发)至结籽成熟生长160d以上.植株高度80～113cm,5月出苗(萌发),8月开花,10月种子成熟.干鲜比1:4.4,茎叶比1:2.0.种子产量538.4kg/hm2(千粒重64.46g),青草产最12809.8kg/hm2.根系发达,生长速度快,种植第5年的植株地上和地下生物量各接近50％,其根系具有很强的同土护坡能力.营养含量中等,可消化吸收率高.阿拉善沙拐枣在我国黄土高原干旱、半干旱地区可作为水土保持和生态建设灌木树种使用,亦可饲用.种植方式以育苗移栽效果最佳,耐粗放管理,种苗成活后不再需浇水、施肥.     

Genetic diversity among varieties of Chia (Salvia hispanica L.)

Chia, Salvia hispanica L., was a staple crop in pre-Columbian Mesoamerica. Despite the great potential of the species as an oilseed crop, little research related to domesticated and wild varieties exists. A study was undertaken to assess genetic diversity among 38 wild and domesticated accessions of S. hispanica collected throughout Mesoamerica by using RAPD markers. Genetic diversity was higher among wild varieties (H _G= 0.15) than all domesticated varieties (H _G= 0.10) and modern commercial domesticated varieties (H _G= 0.02), suggesting a slight loss of diversity accompanying domestication and a near lack of diversity in modern commercial varieties. In addition, the preliminary results indicate that the center of genetic diversity is in the highlands of western Mexico.     

Hedysarum phylogeny mediated by RFLP analysis of nuclear ribosomal DNA – RFLP and Hedysarum phylogeny

The RFLP technique has been employed to investigate phylogenetic relationships between species of the Hedysarum genus. Homologous DNA probes were used to generate patterns from a set of the Mediterranean group. The degree of band sharing was used to estimate genetic distances between species and to draw phylogenetic trees. These are in good agreement with phylogeny based on morphological and isozyme markers, but contain novel insights. The results are discussed in the context of current work in molecular biosystematics in Hedysarum complex. Attempts made in this approach to access the extent of variability at the DNA level occurring with the domestication process have been investigated. With the availability of the tested probes, it has been assumed that the genetic structure is not affected by the domestication process.     

草地蘑菇的分离驯化研究

对在天山草原真菌考察时采到的草地蘑菇(Agaricus pratensis Schaeff.:Fr．)进行菌种分离、驯化栽培,获得初步成功。该菇味道鲜美、产量高,具有重要的开发价值。     

草莓脱毒试管苗炼苗及移栽技术研究

对草莓脱毒试管苗炼苗移栽技术及其影响因素进行了探讨研究,结果表明:培养瓶的开口方法、组培苗的根部冲洗、组培苗定植移栽的密度和方法,以及栽培棚室的温度、湿度等,均能影响草莓脱毒试管苗的成活及生长状况。通过试验,总结出一套适宜于草莓脱毒试管苗炼苗移栽的技术和方法。     

小麦SKC1 like基因的克隆及多样性研究

为了给小麦耐盐分子机制的研究提供参考,以水稻(Oryza sativa L.)耐盐相关数量性状基因SKC1(Shoot K+Content)的cDNA序列(GenBank登录号:DQ148410)为基础,通过搜索GenBank数据库找到2条与OsSKC1同源的普通小麦(Triticum aestivum L.)EST(GenBank登录号:DR734861,CK193616)。根据EST-DR734861设计引物筛选粗山羊草AL8/78(Aegilops squarrosa)BAC文库,通过BAC延伸测序克隆了粗山羊草AL8/78的SKC1-like基因(AeSKC1),进一步根据AeSKC1序列设计特异引物克隆了普通小麦SKC1-like基因(TaSKC1)。对人工合成双二倍体、地方品种和育成品种中TaSKC1的基因多样性分析表明,在驯化过程中TaSKC1瓶颈效应明显,属于驯化基因。     

断根对红掌静水培的影响

研究激素不同浓度、不同处理时间对红掌断根后再生根生长的影响,以及不同充氧周期、营养液浓度对红掌再生根系水培驯化的影响,探求红掌水培时根系耐弱氧的较佳驯化方法.试验结果表明:经激素(根旺)处理后,断根后红掌的生根能力显著增强,其中最适根旺浓度为0.25 g/L,处理时间为3 h;另外,营养液浓度和充氧制度对红掌根系耐弱氧的驯化均有影响,其中营养液浓度对根长的影响显著,最好效果浓度为1.5 C,而充氧制度对根系总量影响显著,其较好的方式为充氧1 h停止2 h间隔式充氧制度.     

大豆籽粒大小和粒形的驯化研究

从野生大豆到栽培大豆的驯化过程中,籽粒大小和形状发生了很大变化,探究这些性状的变化规律能加深对基因驯化机制的认识。以14个野生大豆、45个地方品种和30个育成品种为材料,进行上述性状的偏相关和因子分析。结果表明:栽培品种中百粒重和籽粒大小呈极显著相关,但野生大豆中百粒重和粒长不相关;野生大豆中长宽比是因子分析第1因子的重要成分,而栽培品种并非如此;百粒重与籽粒大小显著相关,与粒形性状不相关。此外,上述结果还通过溧水中子黄豆和南农493-1杂交组合构建的504个正反交F2∶3、F2∶4和F2∶5家系群体的偏相关分析和QTL定位结果予以证实。