Sweet-potato productivity as affected by recurrent use of vines as planting-material

Yield performances of apical shoot cuttings of sweet potato (Ipomoea batatas) obtained from crops raised 2 or 4 times recurrently through vines, were compared with those obtained from tubers. The recurrent use of vines as planting-material did not show any marked variation in market-grade tuber yield, but it significantly decreased vine yield and increased weevil infestation in tubers. Cultivars ‘Cross-4’, ‘RS-5’ differed significantly in performance     

Molecular Cloning and Functional Characterization of a Salt Tolerance-Associated Gene IbNFU1 from Sweetpotato

Iron-sulfur cluster biosynthesis involving the nitrogen fixation(Nif) proteins has been proposed as a general mechanism acting in various organisms.NifU-like protein may play an important role in protecting plants against abiotic and biotic stresses.Based on the EST sequence selected from salt-stressed suppression subtractive hybridization(SSH) cDNA library constructed with a salt-tolerant mutant LM79,a NFU gene,termed IbNFU1,was cloned from sweetpotato(Ipomoea batatas(L.) Lam.) via rapid amplification of cDNA ends(RACE).The cDNA sequence of 1 117 bp contained an 846 bp open reading frame encoding a 281 amino acids polypeptide with a molecular weight of 30.5 kDa and an isoelectric point(pI) of 5.12.IbNFU1 gene contained a conserved Cys-X-X-Cys motif in C-terminal of the iron-sulfur cluster domain.The deduced amino acid sequence had 66.08 to 71.99% sequence identity to NFU genes reported in Arabidopsis thaliana,Eucalyptus grandis and Vitis vinifera.Real-time quantitative PCR analysis revealed that the expression level of IbNFU1 gene was significantly higher in the roots of the mutant LM79 compared to the wild-type Lizixiang.Transgenic tobacco(cv.Wisconsin 38) plants expressing IbNFU1 gene exhibited significantly higher salt tolerance compared to the untransformed control plants.It is proposed that IbNFU1 gene has an important function for salt tolerance of plants.     

蕹菜对镉吸收积累及应用研究进展

综述了镉对蕹菜生长的影响,蕹菜对镉的吸收积累和相关机理,以及蕹菜在修复土壤镉污染和安全生产两方面的前景,为研究及应用蕹菜吸收积累镉提供理论参考。     

分子生物学技术在甘薯中的应用

甘薯是重要的粮食作物,它的遗传背景复杂,分子生物学研究进展落后于水稻、玉米等作物。分子标记技术主要应用于甘薯的遗传图谱构建、遗传多样性分析以及亲缘关系分析等方面。目前,已经构建了数张遗传图谱,亲缘关系分析表明三浅裂野牵牛I.trifida与甘薯有很紧密的亲缘性。基因克隆技术已经应用于甘薯在抗逆、品质以及块根发育等相关基因的分离,为甘薯的分子育种带来了有益的目的基因。在栗子香、新大紫等甘薯品种有转基因的报道,采用农杆菌介导的方法,已经取得了少量的转基因植株。     

根癌农杆菌介导的甘薯遗传转化及转基因植株的再生

以甘薯优良品种"新大紫”的茎尖培养再生植株为试材,经根癌农杆菌介导将甘薯块根贮藏蛋白启动子(Sporaminpromoter)调控下的10kD玉米醇溶蛋白基因导入到"新大紫”中,并获得了转化植株.甘薯品种"新大紫”再生植株的茎切段,与携带有表达载体质粒pSP10Z的根癌农杆菌菌株LBA4404共培养后,在含75mg/L卡那霉素(Kan)的筛选培养基上可     

旋花科植物ITS序列分析

通过提取白色圆叶牵牛基因组的DNA及紫色重瓣圆叶牵牛的DNA,对其内转录间隔区(ITS)序列进行PCR扩增和序列测定.采用BLAST方法,将测序结果在GenBank中进行同源搜索,采用邻接距离矩阵法构建了与其亲缘关系接近的旋花科14个种基于ITS序列的系统发育树,并分析了它们的亲缘关系.结果表明,原牵牛属和番薯属的亲缘关系较近,打碗花属、旋花属与番薯属为旋花科两大亲缘关系较远的类群;疑似新种的紫色重瓣圆叶牵牛并非一个新种,而是属于圆叶牵牛种下分类水平的变种或变型.     

Patterns of defoliation and their effect on the plant growth and photosynthetic characteristics of Ipomoea cairica

In order to determine the susceptibility of Ipomoea cairica to herbivory, the compensatory growth and photosynthetic characteristics of I. cairica plants were measured after simulated herbivory by leaf trimming in three patterns: leaf‐apex removal, leaf‐edge removal, and perforation. The leaf‐edge removal resulted in a significantly reduced total biomass and root biomass of the plants, but the leaf‐apex removal and perforation had no significant influence on the plant growth. The defoliation patterns had significant effects on the photosynthesis of I. cairica. The net photosynthetic rate and stomatal conductance of the plants whose leaf edges had been removed were the highest among the three defoliation patterns and the fraction of absorbed light that is used in Photosystem II photochemistry increased greatly, while the fraction of light energy that is dissipated thermally decreased. The increased photosynthetic rate as a result of the leaf‐edge removal treatment could be attributed to a decrease in stomatal limitation and an increase in the Rubisco content, as well as higher photosynthetic efficiency and less light energy being dissipated as heat. Increased photosynthesis in the plants whose leaf edges had been removed changed the carbon allocation and resulted in less root development. As the expansion of I. cairica primarily depends on clonal growth, smaller roots could limit its uptake of nutrients from the soil. These direct and indirect effects indicate that leaf‐edge‐feeding herbivores could have potential in the biological control of I. cairica.     

甘薯叶黄酮对Ⅱ型糖尿病模型小鼠的降糖及DNA损伤修复作用

【目的】探讨甘薯叶黄酮（FIBL）的降糖作用及其对糖尿病DNA损伤的修复作用。【方法】采用高糖高脂日粮和链脲佐菌素（STZ）建立Ⅱ型糖尿病（NIDDM）小鼠动物模型,然后将其分为模型对照组（DC）、FIBL低剂量组（FTL）、FIBL高剂量组（FTH）和罗格列酮组(RT组),另取正常小鼠作为正常对照组（NC）。其中,正常对照组、模型对照组小鼠每天灌胃0.2 mL dH₂O,FIBL低剂量和高剂量组小鼠每天分别灌胃75 和150 mg/kg 的FIBL,RT组每天灌胃3 mg/kg 罗格列酮,连续灌胃28 d。对小鼠一般情况进行观察,并于灌胃0(灌胃前),7,14,21,28 d尾静脉采血检测血糖;29 d时,断头采血检测血脂,并分离淋巴细胞,采用单细胞凝胶电泳技术(SCGE)检测DNA损伤情况。【结果】动物模型建模成功后,Ⅱ型糖尿病（NIDDM）小鼠存在多饮、多尿、多食,及一定程度的胰岛素抵抗等情况。FIBL治疗结果显示,FIBL能控制NIDDM小鼠体质量的增长;能有效降低NIDDM小鼠的血糖、血脂水平;对NIDDM小鼠的DNA损伤具有修复作用。【结论】甘薯叶黄酮能改善高血糖症状及脂质代谢紊乱状况;可以治疗和延缓NIDDM并发症的发生。     

甘薯渣在食用菌制种及栽培上的应用

在甘薯渣中添加不同比例的棉籽壳和玉米芯进行糙皮侧耳(Pleurotus ostreatus)、金针菇(Flammulinna velutipes)、鸡腿蘑(Coprinus comatus)栽培试验和糙皮侧耳制种试验。结果表明，在纯甘薯渣培养料上菌丝生长速度快，生长势强，菌丝满袋时间与对照相比缩短8～12d，且现蕾早，出菇快，但产量较低，生物学效率比棉籽壳和玉米芯常规培养料(对照)减少35％以上。但甘薯渣培养料可作为糙皮侧耳栽培种的制种材料。