鱼腥草系列食品开发及其接受度评价

以新鲜鱼腥草为主要原料,设计开发鱼腥草辣椒酱、鱼腥草袋泡茶、鱼腥草饮料和鱼腥草纤维蛋糕四种鱼腥草系列加工食品,通过感官评价分析每个产品的风味特点和人群接受度。结果表明,鱼腥草搭配其他配料可以加工成酱、茶、饮料和蛋糕等产品,四个鱼腥草系列加工食品的风味各有特点,其中鱼腥草豆豉辣椒酱和鱼腥草粗纤维蛋糕的接受度较高。通过添加配料改善鱼腥草产品的风味,不但保留了鱼腥草的味道,而且使不喜食鲜鱼腥草的人群可以接受其加工型产品。     

山西芝麻种质资源遗传多样性分析

为了解山西芝麻种质资源遗传多样性,本研究对189份山西芝麻种质资源的10个质量性状和8个数量性状进行遗传多样性分析和聚类分析。结果表明：189份山西芝麻种质资源的表型性状存在较大的遗传差异,质量性状以主茎茸毛量的遗传多样性指数最高,为1.15,以蒴果棱数的变异系数最高,为63.88%;数量性状以节间长度的遗传多样性指数最高,为2.09,以单株产量的变异系数最高,为47.66%;通过聚类分析,将189份山西芝麻种质资源分为4个类群,类群Ⅰ可作为选育八棱、高秆品种的亲本材料,类群Ⅱ为矮秆、短节间特异材料,类群Ⅲ为高产选育目标材料,综合性状较好,可直接作为优异亲本加以利用,类群Ⅳ包含一批单花、高产特异材料。     

南瓜银叶突变体48a的表型特征及其遗传学分析

南瓜银叶突变体48a是在嫩食型中国南瓜中分离筛选到的稳定遗传自交系,银色叶不仅可以作为标记性状应用到育种中,还可为南瓜抗虫、抗病、耐寒等一系列研究提供重要的材料基础。笔者对银叶突变体的表型特征及叶片的解剖结构进行鉴定分析,发现植株整体长势、熟性与野生型无明显差异;成熟叶片正面全部呈银灰色,叶绿素含量明显降低,叶片上表皮细胞与栅栏细胞间明显剥离,存在明显的空隙。利用突变体48a和野生型49a南瓜自交系构建的六世代遗传群体,调查发现F2的绿叶与银叶符合3∶1的分离比,回交群体BC1P1分离比符合1∶1,表明南瓜银色叶性状由单隐性基因控制。     

野生老芒麦种质资源鉴定与基部叶鞘绒毛变异分析

为更好地利用老芒麦(Elymus sibiricus L.)野生资源,本研究从我国青藏高原、西北、华北、东北地区以及国外部分地区共采集了1 723份野生披碱草属种质资源,通过表型特征观测和流式细胞仪检测,共鉴定出了990份野生老芒麦种质,246份垂穗披碱草种质,并测得老芒麦的DNA含量在5.86～7.30 Gb之间,平均DNA含量为6.66 Gb;垂穗披碱草材料的DNA含量在9.50～10.36 Gb之间,平均DNA含量为9.97 Gb。研究结果显示,在西北、华北以及东北地区的部分野生老芒麦材料在苗期基部叶鞘出现了绒毛,分析发现该表型出现的概率与经度和纬度呈极显著正相关关系(P<0.01),与海拔、年年均气温以及年平均降雨量呈极显著负相关关系(P<0.01)。表明老芒麦苗期基部叶鞘绒毛的有无与环境因子之间存在着必然的联系,可能是老芒麦种质应对不同环境类型的适应性机制之一。本研究为老芒麦的形态鉴定提供了新的依据,为老芒麦种质资源挖掘和育种应用提供了材料基础。     

Identification of QTLs related to sugar and organic acid composition in melon using near-isogenic lines

The soluble sugar and organic acid composition of melon (Cucumis melo L.) fruit flesh has become a major focus of plant breeding worldwide in an attempt to improve taste. Thus, sugar and organic acid profiles were characterized using near-isogenic lines (NILs) derived from the Spanish cultivar Piel de Sapo (PS) and the exotic Korean accession Shongwan Charmi (PI 161375). Fruits were cultivated in only one environment. These data were used to map 60 quantitative trait loci (QTLs): 18 for individual sugars, eight for sucrose equivalents, five for the glucose-to-fructose ratio, seven for the total sugar content and 21 for organic acids. Within the QTLs that were associated with the sugar profile, 27 defined the sugar content: eight for fructose, six for glucose, four for sucrose, and nine for sucrose equivalents. Although increased sweetness of selected NILs compared with the parental PS was achieved by an increased glucose or fructose content, only glucose heritability was above 0.5. A total of 21 QTLs (two with positive effects and nineteen with detrimental effects compared with the PS levels) controlled the organic acid profile: l-glutamic, ascorbic and succinic acids (the principal ones) and fumaric, citric, oxalacetic, and isocitric acids. The levels of sugars imparted by the PI 161375 introgression frequently decreased the score grades given to NILs by consumers. Within the 32 QTLs mapped for sensory traits, 27 were associated with lower scores in taste (nine QTLs), sweetness (eight QTLs) or global quality appreciation (nine QTLs); two with increased fruit sourness or sweetness and three with increased fruit bitterness. The QTLs defined herein may assist breeders to understand the overall organoleptic balance (sweetness, sourness, and umami taste) in melon fruit, particularly those located within linkage groups III, V, VI, and VIII to XI.     

寒地梨种质资源表型多样性研究

对寒地梨种质资源表型性状的Simpson和Shannon多样性指数、标准差、变异系数和聚类分析等研究表明幼叶颜色、叶面状态、果实形状、抗寒性、抗梨黑星病、单果质量、可溶性固形物等性状多样性指数较高,变异度大,可为梨育种提供良好变异的群体;尤其是保存了多份极抗寒资源,抗寒性中等资源较少,无抗寒性弱和极弱的资源;果实形状多样性较高,而且性状间分布也较为均匀,可溶性固形物变异系数较大;大果型、抗梨黑星病类型资源分布较少,尚需收集、增加果个大、高抗病资源。     

观赏向日葵品种北热带地区物候特征、表型性状评价

观赏植物的精准应用有助于提升城市公园品质。对湛江地区14个观赏向日葵Helianthus annuus品种进行夏季田间引种试验,观测、记录和分析其8个物候特征和14个表型性状,结果表明各观赏向日葵品种间物候特征具有差异性,表型变异较为丰富,14个品种聚类为四大类群。进一步探讨了观赏向日葵应用的品种选择、种植调节及配植方式,为观赏向日葵多重配植方式、应用分类和节庆精准应用提供了科学依据。     

不同来源大豆种质资源的田间鉴定与筛选

旨在评价不同生态区大豆种质资源表型性状遗传多样性,为亲本选择和品种改良提供科学依据。以1 580份来源于国外和中国北方、黄淮海、南方生态区的大豆种质资源为对象,分析21个形态描述型性状的遗传多样性,并对13个数量性状的遗传变异及其相关性进行综合分析。结果表明：21个描述型性状的Simpson多样性指数平均值在国外、中国北方、黄淮海、南方及总资源群体中分别为0.345 9、0.347 1、0.345 9、  0.322 4、0.357 7,荚色Simpson多样性指数最大,叶色Simpson多样性指最小。底荚高度、有效分枝数、单株荚数、单株粒数、株高、百粒质量、单株粒质量的遗传变异系数均大于30%,初花时间、主茎节数、茎粗、荚长、荚宽的遗传变异系数为20%～10%,生育时间的遗传变异系数小于10%。13个数量性状的Simpson多样性指数平均值在国外、中国北方、黄淮海、南方及总资源群体中分别为0.813 6、0.831 1、0.825 9、0.836 9、0.826 5,说明该批大豆种质资源多样性丰富。相关分析表明,单株粒质量与其他12个重要农艺性状呈极显著正相关。通径分析发现百粒质量、单株粒数对单株粒质量的正向效应最大,其次为茎粗、单株荚数,而荚宽、株高、初花时间有负向效应。本研究揭示了该批大豆种质资源表型性状的遗传特点及其相互关系,以大豆单株产量构成性状为综合指标,结合生育时间表现,筛选出30份高产特异大豆种质,为合理选择亲本形成优势性状互补以进行大豆高产品种改良和选育提供参考。     

Phenotypic variation in Azospirillum brasilense Sp7 does not influence plant growth promotion effects

The Azospirillum genus comprises free-living, plant growth-promoting, nitrogen-fixing bacteria found in the rhizosphere of plant roots. Azospirilla are able to promote plant growth mainly through improvement of root development. Bacterial surface components, such as extracellular polysaccharides and proteins, are involved in root colonization. Phase variation – or phenotypic variation – is one of the mechanisms by which microorganisms adapt to environmental changes. This phenomenon is characterized by the presence of a sub-population of the bacteria presenting a different phenotype relative to the major population. In this study we characterized phenotypic variation of Azospirillum brasilense Sp7. When plated on solid media, some A. brasilense colonies were shown to possess a much more mucoid morphology, producing 7.5–8 times more exopolysaccharide with different monosaccharide composition than the parental strain Sp7. The rate of appearance of this kind of variant colonies was 1 in 5000, in agreement with the accepted rate for the phase/phenotypic variation phenomenon. The variants were significantly more resistant to heat and UV-exposure than the parental strain and displayed genomic changes as seen by the different band patterns following ERIC-PCR, BOX-PCR and RAPD analyses. In plant inoculation experiments under greenhouse conditions, with maize, wheat, soybean and peanuts, the EPS overproducing variants performed as similar as the parental strain. Therefore, EPS overproduction did not confer an apparent advantage to A. brasilense in terms of induction of plant growth promotion.