彩色马铃薯花青苷研究进展

彩色马铃薯含有丰富的花青苷,具有一定的保健功能。主要介绍了花青苷的生理功能,分析了彩色马铃薯中花青苷的提取、纯化技术及其分子结构,总结了花青苷定性分析方法及检测技术。     

不同流通温度与包装方式对采后甜玉米穗品质的影响

研究了不同流通温度和包装方式处理对甜玉米穗采后品质和营养成分的影响。结果表明,甜玉米在常温条件下流通,其营养成分和品质变化较快,带苞叶处理的最佳流通时间为2 d,PE包装最佳流通时间为3 d;低温可以较好地保持甜玉米的营养成分,带苞叶处理的甜玉米最佳流通时间为5 d,PE包装处理的最佳流通时间为6 d;低温结合PE包装处理可以减缓水分散失以及VC含量的下降,而对可溶性固形物,可溶性蛋白、水溶性氨基酸以及可溶性糖含量影响较小。     

甘薯糠腐茎线虫病组织病理学扫描电镜研究

利用扫描电子显微镜对被甘薯糠腐茎线虫（ＤｉｔｙｌｅｎｃｈｕｓｄｅｓｔｒｕｃｔｏｒＴｈｏｒｎｅ）侵染的甘薯组织细胞的损伤情况进行了观察,结果表明：与健康甘薯相比,轻一中度侵染的病薯细胞失水,雏缩,细胞间隙加大,淀粉粒颗粒变小,大部分细胞出现及变形等病理变化,同时可见许多正在侵染的线虫;患病严重的薯块内细胞严重失水,皱缩,细胞间呈现大的空隙,维管组织变形,有的破碎,细胞内淀粉数量明业减少甚至完全丢失,     

Genetic variation of sweet potatoes (Ipomoea batatas L.) cultivated in Chile determined by RAPDs

RAPD (randomly amplified polymorphic DNA) technology was applied to analyze the genetic variability of sweet potato germplasm existing in Chile and elsewhere. Analysis of 28 cultivars from all over the world showed polymorphic bands with all 18 primers tested. A total of 124 RAPD bands were scored with an average of 6.9 polymorphic bands per primer. These results confirm that sweet potato exhibits high genetic variation. Two groups were distinguished: one containing Peruvian cultivars, and another containing cultivars from the rest of the world. Analysis of 14 accessions from Central Chile and one from Northern Chile showed polymorphic bands with 24 of 26 primers tested, but almost all of the 140 polymorphic bands merely showed the distinctness of the Northern accession. The almost complete uniformity of the other 14 accessions shows that sweet potato germplasm collected in Central Chile has very little genetic variability and may be derived from a single cultivar. Based on these results and on historical records, some hypotheses are proposed to explain the origin of sweet potatoes cultivated in Chile. This revised version was published online in July 2006 with corrections to the Cover Date.     

Cytological studies on adventitious shoots and minitubers of a monoploid potato clone

Summary A three step procedure for adventitious shoot regeneration on leaf explants of monoploid potato clone H7322 and a minituber induction procedure on stem segments have been described. Chromosome counts on 92 adventitious shoots showed that 85% of them had been polyploidized, i.e., 71% were diploid, 1% tetraploid, and 13% were mixoploid. Cytophotometric studies on nuclei of soil grown tubers of tetraploid cv Astarte, of 1x, 2x and 4x adventitious shoots of H7322, and of diploid H²578 showed in all cases polyploidization with prominent classes up to 8C and 16C. However, nuclei of pith cells of 5 weeks old minitubers which had developed on monoploid H7322 itself or on 1x adventitious shoots of H7322 showed predominantly 1C and 2C values. Pith cells of minitubers of monoploid H7322 were screened, after iodine staining, for the presence of variant cells containing reddish-brown staining (amylose-free) starch. In more than 75% of the investigated minitubers one or a few of such variant cells were found indicating that such a variation occurs in minitubers of monoploid potato and that this variant character is expressed in cells of vegetative storage organs like potato tubers.     

The transfer of the synaptic gene (sy-2) from 1EBN Solanum commersonii Dun. to 2EBN germplasm

Summary Crosses of a synaptic mutant (sy-2) of 2x(1EBN) S. commersonii Dun. with 2x(2EBN) S. chacoense Bitt. resulted in the production of 3x(2EBN) hybrids. Low levels of 2n egg production in these hybrids allowed subsequent crosses to be made with 4x(4EBN) cultivars, resulting in 5x(4EBN) S. commersonii-S. chacoense-Group Tuberosum hybrids. Seed set in these crosses averaged 0.22 seeds per fruit. Fifty-four unspotted seeds were produced in 1225 crosses of the 5x(4EBN) hybrids with 2x(2EBN) Group Phureja haploid extraction clones carrying dominant seed spot markers. These seeds yielded a total of 15 confirmed haploids having a diploid (2n=2x=24) or near diploid chromosome number. One haploid clone recovered displayed a synaptically abnormal phenotype similar to the original S. commersonii synaptic mutant. Preliminary test crosses of these haploids indicated that all haploids produced were 2EBN.This method for the transfer of alleles across EBN levels holds promise for the recovery of both qualitative and quantitative traits from 1EBN species. In these recovered, cross-compatible forms, clones with desired characteristics may be selected and easily incorporated into breeding programs.     

The Importance of the Bolivian Wild Potato Species in Breeding for Globodera pallida Resistance

Screening for resistance to the potato cyst nematode, Globodera pallida, in potatoes from. Bolivia, was carried out in 1983 and 1984, using a mixture of four nematode populations representing pathotypes Pa₁, Pa₂ and Pa₃ From the 66 accessions of 17 species and subspecies evaluated, highly resistant genotypes were identified in 21 accessions from seven species. All had Pf/Pi values of 2 or less, whereas the susceptible control, Solanum tuberosum cv. ‘Disiree’ had Pf/Pi values of more than 2G in both tests. Two diploid wild species, S. brevicaule and S. leptophyes, showed the best resistant. The geographical distributional of resistant populations and the evolution of resistance in wild potato populations are discussed.     

棉株载铃量对其主要生育性状的影响

采用 熟性不同 的３ 个陆 地棉 品种 ,在 肥水 充 足的 生 长条 件下 ,研 究了 棉 株不 同载 铃 量对其主要 生育性状 的影响 。结果表 明, 棉株 载铃 量 对株 高、果枝 总长 、果 节总 数均 有 极强 的 影响 ,其影响强 度随载 铃量的增 加而增加 ,累积 影 响量 随棉 株 生长 发 育时 间的 延 长而 增大 ;但 棉株 载 铃量对主茎 节数、果 节平均长 度影响 不显 著。 由此 分析 了 蕾铃 脱 落和 棉株 旺 长之 间的 关 系,以 及 棉株在一定 地力条 件下适宜 的单株载 铃量。     

陆地棉×亚洲棉F_0成胚频数与亲本主要产量性状配合力的关系

陆地棉×亚洲棉F_0成胚频数主要受母本陆地棉的影响,不同的7个陆地棉品种间存在着显著差异.成胚频数高的6901和朝阳1号,单铃子棉重、单铃种子数、子指一般配合力亦均高;而成胚频数低的6913和黑山棉,上述各性状的一般配合力也均低.在7个父本亚洲棉中,与陆地棉杂交当代成胚频数高的束鹿白花和完紫,其子指的一般配合力也较高.因此,选择单铃子棉重、单铃种子数、子指一般配合力较高的陆地棉作母本与子指一般配合力较高的亚洲棉作父本杂交,可以显著提高种间杂交当代的成胚频数.     

Assignment of Endosperm Balance Numbers to the tuber-bearing Solanums and their close non-tuber-bearing relatives

The Endosperm Balance Number (EBN) of over 80 species and subspecies of the tuber-bearing Solanums and their close non-tuber-bearing relatives representing 13 taxonomic series has been determined, with no species assigned to more than one EBN level. Among North American species, most diploids are 1EBN, most tetraploids are 2EBN and all hexaploids are 4EBN; however, among South American species most diploids are 2EBN, most tetraploids are 4EBN and again all hexaploids are 4EBN. Thus species may be isolated from others of the same ploidy level by EBN differences, e.g., 4×(2EBN) from 4×(4EBN), while other species differing in ploidy but having the same EBN may be intercrossed, e.g., 4×(2EBN) and 2×(2EBN). Chromosome doubling or 2n gametes can be used to make a lower EBN species compatible with a higher EBN species. These findings also explain the major crossing difficulties previously inherent in the use of North American species in potato improvement. They also have direct implications for potato improvement, barring the occurrence of other incompatibility barriers. Any 4×(4EBN) cultivar is endosperm compatible and thus will cross with 4×(4EBN) and 6×(4EBN) species. The 2×(2EBN) haploids of 4×(4EBN) cultivars likewise will hybridize with 2×(2EBN) and 4×(4EBN) species. All 2×(1EBN) species are crossable with 2×(2EBN) haploids through 2n gametes or chromosome doubling.Cooperative investigation of the U.S. Department of Agriculture, Agriculture Research Service, and the Wisconsin Experiment Station.