FaesCAL基因在同型长花柱甜荞中的表达分析

为探究同型长花柱甜荞花的发育调控的分子机制，从同型长花柱甜荞中分离得到1个全长984 bp的CAL同源基因cDNA 序列，命名为FaesCAL。FaesCAL基因包含长726 bp的完整开放阅读框，编码1个由241个氨基酸残基组成的MADS-box转录因子。蛋白序列比对及系统发育分析结果表明：FaesCAL 蛋白属于MADS-box转录因子中的CAL进化系，包含1个由57个氨基酸残基组成的高度保守的 MADS 结构域和1个由68个氨基酸残基组成的次级保守区域的 K 结构域。通过实时荧光定量(qRT-PCR)检测FaesCAL基因在同型长花柱甜荞中的组织表达特异性显示:FaesCAL基因主要在根、雄蕊、花被片和5 d果实中表达，在雌蕊中表达量很低，在茎和叶片中不表达，并且在雄蕊和花被片中的表达量极显著高于其他组织（LSD， P<0.01）。进一步通过qRT-PCR检测FaesCAL基因在甜荞花芽分化5个关键时期表达量的动态变化显示：FaesCAL基因的表达量在开花前雌雄蕊成熟时表达量最高，在雄蕊花丝的迅速伸长和花被片原基的出现时期的表达量其次。推测该基因参与了甜荞的成花转变，并在雄蕊以及花被片的发育中发挥作用。     

野生牧草金荞麦与贵州省推广牧草栽培效益比较试验初报

金荞麦Poyigonum cymosum是一种药饲兼用的贵州野生植物资源,通过金荞麦与贵州省目前主要推广牧草的田间试验比较,研究金荞麦和推广牧草资源的产量、品质和饲用的不同特点。试验初步认为:金荞麦是一种高产优质的牧草资源,其产量与菊苣Cichorium intybus相似,比一般推广牧草如苜蓿Medicagosativa等高出2~3倍。其粗蛋白含量与菊苣相似,接近苜蓿。金荞麦的适口性好,耐瘠抗劣性强,易繁殖成活,有较大的推广潜力。     

苦荞麦毛状根的诱导研究

利用发根农杆菌Ri1601浸染苦荞植物预培养2d的叶片外植体,经不同时间的共培养和除菌培养后获得毛状根。经硅胶薄层色谱板检测表明,发根农杆菌Ri1601和苦荞叶片上未经转化产生的不定根都不含有冠瘿碱;而经发根农杆菌Ri1601遗传转化后所产生的毛状根有冠瘿碱的存在。因此,可确定苦荞叶片上产生的毛状根为发根农杆菌Ri1601转化所得。建立了用发根农杆菌Ri1601诱导苦荞植物叶片产生毛状根的有效方法。     

Phylogenetic analysis of AGAMOUS sequences reveals the origin of the diploid and tetraploid forms of self-pollinating wild buckwheat,Fagopyrum homotropicum Ohnishi

Fagopyrum homotropicum Ohnishi is a self-pollinating wild buckwheat species indigenous to eastern Tibet and the Yunnan and Sichuan Provinces of China. It is useful breeding material for shifting cultivated buckwheat (F. esculentum ssp. esculentum Moench) from out-crossing to self-pollinating. Despite its importance as a genetic resource in buckwheat breeding, the genetic variation of F. homotropicum is poorly understood. In this study, we investigated the genetic variation and phylogenetic relationships of the diploid and tetraploid forms of F. homotropicum based on the nucleotide sequences of a nuclear gene, AGAMOUS (AG). Neighbor-joining analysis revealed that representative individuals clustered into three large groups (Group I, II and III). Each group contained diploid and tetraploid forms of F. homotropicum. We identified tetraploid plants that had two diverged AG sequences; one belonging to Group I and the other belonging to Group II, or one belonging to Group II and the other belonging to Group III. These results suggest that the tetraploid form originated from at least two hybridization events between deeply differentiated diploids. The results also imply that the genetic diversity contributed by tetraploidization of differentiated diploids may have allowed the distribution range of F. homotropicum to expand to the northern areas of China.     

Variation in Seed Shape and Husk Color in Japanese Native Cultivars of Common Buckwheat (Fagopyrum esculentum Moench)

Abstract

The variation in seed shape and husk color was investigated in 56 Japanese native cultivars of common buckwheat. Analysis of variance revealed highly significant differences among the cultivars in seed shape characteristics and husk colors. The 1000-seed weight (1000-SW) ranged widely, from 20.4 to 39.0 g, among the cultivars. The cultivars collected from the Kanto region of the mainland had a large length and width of seed and heavy 1000-SW. On the other hand, the cultivars from the Chugoku and Shikoku regions of Japan had a small length and width of seed. The length and width of seeds showed a high positive correlation. The cultivars with a high 1000-SW showed a slight difference between length and width of seed and were typically the triangular type in seed shape. The length/width ratio (L/W) depended on the width rather than the length of seed, though both were negatively correlated with the L/W. Highly positive correlations were found among the L*, a* and b* husk color value. The L* showed a highly positive correlation with growth duration, and the husk color of the cultivars became more deep black as growth duration decreased. The husk color of the cultivars from the Kyushu region (long growth duration) was grayish brown, but that of the cultivars from Nagano Pref. (the shortest growth duration) was characterized as typically deep black. The cultivars collected at lower latitude regions tended to have a lighter color of husk than those from higher latitude regions. The cultivars from the Tohoku region showed a smaller variation for seed size characteristics and 1000-SW, and the cultivars from the Kyushu region showed a smaller variation for husk color.     

甜荞子粒总黄酮提取工艺的优化

为了充分利用荞麦(Fagopyrum esculentum)资源,以内蒙古甜荞子粒为研究对象,利用乙醇提取法提取子粒中总黄酮,并对其工艺进行优化.最终得出荞麦子粒总黄酮提取的最佳工艺条件为乙醇体积分数65％,水浴时间80 min,水浴温度60℃,料液比1:20(m/V,g:mL).     

Genetic diversity of Fagopyrum homotropicum, a wild species related to common buckwheat

Nineteen natural populations of Fagopyrum homotropicum, a self-fertilizing close relative of common buckwheat, from the Yunnan and Sichuan provinces of China were investigated for their chromosome number and allozyme variation at 16 loci of 11 enzymes. Three populations, 'Deqin', 'Zhongdian', and 'Xiancheng', were revealed to be allotetraploid. Judging from allozyme constitution of the tetraploid and their possible progenitors, diploid progenitors are probably the diploid population of F. homotropicum from Lijiang and a natural population of F. esculentum ssp. ancestralis. Diploid populations of F. homotropicum are fixed for a given allele at almost all isozyme loci. Allozyme variation has been maintained in natural populations mainly by fixing different alleles in different populations, as they are highly differentiated among the populations (G_st = 0.969). The position of populations in the phylogenetic tree constructed from genetic distance nearly corresponded with the geographical position of the populations.     

Effects of buckwheat growth on variation of aluminum and major metals in root‐zone soil solutions

The variation in and relationships between aluminum and other major metals including Ca, Mg, Mn, and K in root‐zone soil solutions were studied by growing buckwheat (Fagopyrum esculentum Moench. cv. Jiangxi), an Al accumulator, in pots filled with an acid soil amended with CaCO₃ and unamended controls with a preinstalled nondestructive soil‐solution sampler. Soil solutions were collected every 7 d with a syringe connected to the sampler. The results showed that pH of the soil solution was not the only factor controlling the concentration of Al. Significant positive linear correlations were found between Al and Ca as well as between Al and Mg in soil solutions from the controls. The ratio of base cations (BC, Ca+Mg) to Al might partly explain the high Al resistance of buckwheat. Oxalate secretion from roots significantly activated Al in acid soils, which may be important for changes of Al in soil solutions, but it also caused decreased concentrations of Ca, Mg, and Mn. It is concluded that the variation of metal concentrations including Al, Ca, Mg, and Mn is a holistic effect involving competition for exchange sites among Ca, Mg, H, and Al, the chelation by oxalate secreted from roots, and metal uptake by buckwheat.     

栽培荞麦种子醇溶蛋白遗传多样性分析

利用A-PAGE（Acid-polyacrylamide gel electrophoresis）对来源于7个国家的76份栽培荞麦（苦荞54份,甜荞22份）醇溶蛋白遗传多样性进行评价。结果表明,荞麦醇溶蛋白位点存在丰富的等位变异,共分离出18条迁移率不同的谱带,每份材料具有6~12条不等,平均9.5条,多态性带占88.89%。材料间平均遗传相似系数（GS）为0.777,变幅为0.389~1.000。在GS为0.63的水平上供试材料可聚为苦荞和甜荞两大类,绝大部分来自于相同或相似生态地理环境的材料聚成一类,表明荞麦醇溶蛋白所揭示的遗传关系与地理来源有较高的相关性。     

荞麦幼苗根对热胁迫的生理应答

通过测定热驯(37℃)、经热驯再热胁迫(37℃→44℃)和直接热胁迫(44℃)下荞麦(Fagopyrumesculentum Moench)幼苗的根生长量、抗坏血酸(AsA)、丙二醛(MDA)、相对含水量(RWC)和相对电导率的变化,探讨荞麦幼苗根对热胁迫的生理应答。结果表明,荞麦幼苗根的生长量、RWC和AsA含量随胁迫温度的升高而降低,相对电导率和MDA含量随胁迫温度的升高而增加;热驯提高了根部对后继热胁迫的耐性,使根的生长量、RWC和AsA含量高于直接热胁迫幼苗,MDA含量和相对电导率低于直接高温胁迫的。显然,热胁迫对荞麦根的生长造成不利影响,热驯在一定程度提高了根的耐热性。