Effect of Different Plant Growth Regulators on Callus Induction and in vitro Rapid Propagation of Wild Petunia Juss.

In this study,the seeds of wild Petunia Juss.were used as explants to investigate the optimal condition for tissue culture.Several different kinds and concentrations of growth regulators were adopted to produce more multiple bud clumps,callus or roots in this study.The experiments may provide experimental foundation for the rapid propagation technology and establishment of tissue culture system for wild Petunia Juss.     

矮牵牛茎段植株再生体系的建立

将矮牵牛Petunia hybrida Vilm的茎段接种在MS附加不同激素的培养基上进行愈伤组织诱导.结果表明:在MS BA1.0 mol.L-1 NAA1.0 mol.L-1的培养基上可以形成愈伤组织,而且经过继代培养仍可形成愈伤组织;茎段或愈伤组织接种在MS BA1.0 mol.L-1 NAA0.1 mol.L-1的培养基上可以形成不定芽,且诱导率达100%;健壮的高1.5~2.0 cm的不定芽接种在1/2MS IBA0.5 mol.L-1 AC1.0 g.L-1的培养基上,其生长根状况良好,生根率达100%.     

应用正交设计进行矮牵牛组培苗生根条件的筛选

采用正交设计方法对矮牵牛组培苗生根的条件进行筛选。试验表明1/2MS+BA 0.1 mg.L-1+IBA 0.8 mg.L-1+NAA 3.0 mg.L-1,蔗糖30 g.L-1的培养基对矮牵牛组培苗生根最有利。     

外源 Ca^2 ＋对干旱胁迫下矮牵牛幼苗抗旱性及生物量的影响

[目的]为了了解外源Ca^2＋对干旱下矮牵牛幼苗生长的影响。[方法]采用盆栽控水的方法,研究了在干旱胁迫和复水条件下,施用不同浓度CaCl2对矮牵牛幼苗抗旱性和生物量的影响。[结果]随着干旱胁迫的加深和时间的延长,施加CaCl2均能显著降低矮牵牛的旱害指数,增加矮牵牛幼苗的干物质积累量和干物质根冠比,减小干旱胁迫对矮牵牛造成的伤害;复水处理后,施加CaCl2的各处理旱害指数均显著低于对照,干物质积累量和干物质根冠比均显著高于对照。[结论]在干旱胁迫过程中,施用CaCl2能增加矮牵牛幼苗的干物质积累量和干物质根冠比,并减小干旱胁迫对矮牵牛造成的伤害,其中以40mmol／LCaCl2对矮牵牛效果最好。     

丹麦品氏托普基质对矮牵牛穴盘苗发芽和生长的影响

为实现矮牵牛的大规模工厂化育苗,研究了不同基质对矮牵牛种子发芽和幼苗生长的影响。结果表明:与素土和普通草炭基质相比,丹麦品氏托普基质大大地缩短了矮牵牛生育期。丹麦品氏托普基质处理下的矮牵牛发芽率、发芽势和冠幅均高于其它两种基质处理,同时,植株感病率低,杂草生长减少。     

Characterization of cytoplasmic male sterility in Petunia hybrida. I. Localization,composition and activity of esterases

Summary Anthers of male fertile, cytosterile and restored male fertile clones of Petunia hybrida were compared for esterase activity and composition in subsequent stages of microsporogenesis. Three methods were applied (i) ultra-thin layer isoelectric focussing on polyacryl amide gels, (ii) quantitative spectrophotometrical assay, (iii) histochemical determination of total esterase activity associated to the azo-coupling method (Pearse, 1972).In male fertile and restorer idiotypes the isozyme patterns were quite similar. Both the number and intensity of bands increased gradually till the tetrad stage. In contrast, esterase activity in cytosterile anthers remained at a low level and hardy any new bands showed up in later stages. This unvariable, low activity level in cytosterile anthers was also found in the spectrophotometric assay. Histochemical determinations revealed that in male fertile anthers esterase activity is concentrated in the outer tapetal layer at late prophase and that it accumulates there till the early microspore stage. In male sterile anthers esterase accumulation in the tapetal cells stops at the moment that tapetal breakdown becomes visible. This suggests that differences in esterase activity and composition are an effect rather than a cause of the failing pollen formation.     

Characterization of cytoplasmic male sterility in Petunia hybrida and Zea mays. Localization and activity of cytochrome c oxidase

Summary Anthers of male fertile, cytoplasmic male sterile (cms), and restored male fertile Petunia hybrida, are analyzed for cytochrome c oxidase (cox) activity in subsequent stages of microsporogenesis, and compared with anthers of male fertile, cms-S and cms-C Zea mays. The cox activity is determined in anther extracts and cytochemically. In petunia anthers, the first differences in cox activity occur from meiosis onward. However, at these stages, the initial symptoms of degeneration are already apparent. It is suggested that the decline in enzyme activity of the cms petunia anthers is the result rather than the cause of the non-formation of functional pollen.In maize anthers, the cox activity of sterile-type anthers is reduced in comparison with fertile-type anthers from premeiosis onward. There are also consistent cytochemical differences in the mitochondrial organization of cox activity between pollen of cms-S and male ferile maize anthers. In fertile-type mitochondria, the DAB reaction product indicating cox activity is localized in the cristae and within the space between the outer and inner limiting membranes of the organelles. In mitochondria of pollen of cms-S maize, cox activity is only observed between the outer and inner membranes of the mitochondria. The biochemical and cytochemical differences are observed at stages of development at which no structural signs of degeneration are apparent. The results suggest that cms in maize correlates with deviations in cytochrome c oxidase activity.Abbreviations cox cytochrome c oxidase - DAB 3,3-diaminobenzidine     

Discriminating styles (DS) and pollen-mediated pseudo-self compatibility (PMPSC) in Petunia hybrida hort

Summary Discriminating styles (DS) in Petunia hybrida discriminate among incompatible pollen sources with pollen-mediated pseudo-self compatibility (PMPSC) similarly to those in Nemesia strumosa. Both species exhibit a single-locus gametophytic self-incompatibility system. Correlation of PMPSC to PSC level of the male was not universal and DS/PMPSC operated in heterozygous S genotypes. PSC levels of progenies generated from compatible or incompatible bud pollination were not significantly different from those of open-flower pollination of a DS plant with a given male, suggesting that DS did not select among male gametophytes for increased PSC.Scientific Journal Series Paper Number 13,077 of the Minnesota Agricultural Experiment Station.     

Winter environment increases self seed yield in self-incompatible (SI) Petunia hybrida clones

Summary SI inbreds of P. hybrida and crosses between self-incompatible (SI) petunia plants were brought to flower under winter and summer glasshouse conditions. SI response, as measured by self seed, ranged from zero seed set under both conditions to low or zero seed set during the summer and high seed set during the winter. Some plants produced comparable seed yields during either pollination time. Increased expression of pseudo-self-compatibility (PSC) during the winter months was attributed to a breakdown of the Si system by the low light conditions of Minnesota winters (45°N). Genotypic differences within and between populations in the winter provided differences facilitating selection for increased SI. These differences were masked in some populations by the summer environmental conditions. The use of simulated or natural low light conditions as a technique for selecting for SI should increase selection efficiency.Scientific Journal Series Paper Number 10,499 of the Minnesota Agricultural Experiment Station.