Somatic hybridization of sexually incompatible petunias: Petunia parodii,Petunia parviflora

Summary Somatic hybrid plants were regenerated following the fusion of leaf mesophyll protoplasts of P. parodii with those isolated from a nuclear-albino mutant of P. parviflora. Attempts at sexual hybridization of these two species repeatedly failed thus confirming their previously established cross-incompatibility. Selection of somatic hybrid plants was possible since protoplasts of P. parodii would not develop beyond the cell colony stage, whilst those of the somatic hybrid and albino P. parviflora produced calluses. Green somatic hybrid calluses were visible against a background of albino cells/calluses, and upon transfer to regeneration media gave rise to shoots. Shoots and the resultant flowering plants were confirmed as somatic hybrids based on their growth habit, floral pigmentation and morphology, leaf hair structure, chromosome number and Fraction 1 protein profiles. The relevance of such hybrid material for the development of new, and extensively modified cultivars, is discussed.     

Genesis of microspore-derived triploid petunias

Summary A total of 61 microspore-derived plants of Petunia parodii were grown to maturity revealing a predominent population of triploids, 80.3%. Cytological investigations, together with the evidence from microfluorimetry, suggest that the origin of these triploids was due to the fusion of interphase nuclei in two different pathways. In the majority of embryogenic microspores, a vegetative nucleus of 1C DNA content fused with an endo-reduplicated 2C DNA generative nucleus at the binucleate stage and produced true triploid embryoids and plantlets (A pathway). Where this fusion failed, both the vegetative and the generative nuclei divided separately and in the multinucleate microspore two or more daughter nuclei fused to form a mixoploid embryoid. Such mixoploid embryoids produced a mixed population of plants with various ploidy levels as well as ploidy polymorphism within an individual. Since the triploids are morphologically superior with a faster growth rate than their diploids and related tetraploids, a predominent population of triploid plants was obtained from such mixoploid embryoids (B pathway). By low temperature treatment of the anther-donor buds, the embryogenic response of microspores was enhanced up to 5-fold.     

水杨酸处理对采后园艺产品的作用

本文结合作者自己的研究结果 ,综述了水杨酸对园艺产品的采后作用 (包括延长切花保鲜期、减轻果实腐烂、推迟洋葱等产品的发芽和对果蔬产品贮藏期间品质、呼吸速率、乙烯释放、抗逆、活性氧代谢方面影响 )的研究进展 ,并对这些结果进行了分析 ;对高浓度外源SA处理引起的负面作用以及存在的一些问题进行了探讨     

姜科黄姜花复合体的形态特征及其分类群界定

为进行黄姜花复合体(Hedychium flavum Complex)的种类鉴定,对采自贵州、重庆、四川、云南、广西等地的标本和移栽后的植株进行形态观测和性状分析。结果表明,小花香气、叶舌、苞片、唇瓣、侧生退化雄蕊和果实等的形态特征是黄姜花复合体种类鉴定的重要指标。据此,把H. panzhuum Z. Y. Zhu归入H. flavum Roxb.中;把H. emeiense Z. Y. Zhu归入H. chrysoleucum Hook.中,而不是归入H. flavescens。该复合体包含H. flavum Roxb.、H. chrysoleucum Hook.、H. bipartitum G. Z. Li及待定种Hedychium sp.,共4种。     

Steady state kinetic mechanism of the Escherichia coli coenzyme A transferase.

Developing chloroplasts isolated from greening cotyledons and isolated etioplasts were capable of synthesizing and accumulating Mg-protoporphyrin IX monoester and longer wavelength metalloporphyrins when incubated in the dark in the presence of protoporphyrin and cofactors. These results constituted the first unambiguous demonstration of the insertion of magnesium into exogenous protoporphyrin in a cell-free system from higher plants. The metalloporphyrin synthetic activity did not occur in the absence of the plastids or when the plastids were heated in a 100 °C water bath for 2 min. It is thus suggested that, in higher plants, the in vitro insertion of magnesium into protoporphyrin is an enzymatic reaction.     

RSAP分子标记技术在园艺植物研究中的应用

限制性位点扩增多态性(RSAP)是一种基于PCR的新型植物分子标记技术,具有操作简便、结果稳定、效率较高的特点。该技术以植物基因组上广泛分布的限制性位点位为靶标,通过独特的引物设计和PCR扩增程序,无需限制性酶切环节,只要一个简单的PCR,即可产生基于植物限制性位点的多态性标记。阐述了RSAP的原理与流程,对该技术的优势和应用情况做了总结,并对其前景进行了展望。     

园艺植物细胞的超微结构研究

细胞是生物体最基本的结构和功能单位。综述了园艺植物的器官生长发育过程中细胞的超微结构研究,果实发育过程中的组织及细胞超微结构研究,逆境下不同器官细胞超微结构变化的研究。指出了当前研究中的不足及今后的发展方向。     

A role for sialic acid containing substrates in the exocytosis-like in vitro interaction between adrenal medullary plasma membranes and chromaffin granules

The “in vitro” interaction between bovine adrenal medullary plasma membranes and chromaffin granules has recently been proposed as a putative cell-free model for exocytosis because calcium ions specifically control the plasma membrane-induced release of 10^?7 and 10^?5 M. Addition of ruthenium red or pretreatment with neuraminidase gradually blocks this interaction indicating that sialic acid containing substrates may be of major importance. These observations and similar results obtained by other authors working on different systems suggest a role for sialic acid containing moieties in exocytosis.     

The effect of the plant cell inhibitor propachlor (alpha-chloro-N-isopropyl-acetanilide) on the cell cycle of L1210 cells as evaluated by flow cytometry

Previously it was reported that the herbicide propachlor (alpha-chloro-N-isopropyl-acetanilide) has a strong inhibitory effect on the proliferation of L1210 mouse leukemia cells. It is now demonstrated that propachlor treatment causes L1210 cells to accumulate in the G1 phase as determined by flow cytometric analysis. This effect of propachlor is dose-dependent with more than 90% of G1 cells accumulating at 10 microM. Kinetic experiments demonstrated that the accumulation of cells in G1 starts in about 10 hours, and increased for up to about 44 hours of incubation with 10 microM propachlor. Treated cells can be revised to a normal DNA distribution by removing propachlor.     

Applications of free living plant growth-promoting rhizobacteria

Free-living plant growth-promoting rhizobacteria (PGPR) can be used in a variety of ways when plant growth enhancements are required. The most intensively researched use of PGPR has been in agriculture and horticulture. Several PGPR formulations are currently available as commercial products for agricultural production. Recently developing areas of PGPR usage include forest regeneration and phytoremediation of contaminated soils. As the mechanisms of plant growth promotion by these bacteria are unravelled, the possibility of more efficient plant-bacteria pairings for novel and practical uses will follow. The progress to date in using PGPR in a variety of applications with different plants is summarized and discussed here.