香菇双单杂交后代不同发育阶段酯酶同工酶研究

选用香菇野生株分别与栽培株及杂交株进行双单杂交 ,得到 8个杂交后代 ,且具有结实能力 ,分别对液培 2 0d杂交后代菌丝与液培原基酯酶同工酶进行了比较研究。结果表明 ,液培 2 0d菌丝菌株间酯酶同工酶酶谱显示出多样性 ,可以作为鉴定菌株的辅助遗传标记 ,而原基菌株间酯酶同工酶酶谱谱带较少 ,呈现趋同效应 ,不宜作为鉴定香菇菌株的辅助遗传标记。     

香菇半亲和双单杂交研究初报

选用一栽培株苏香两种孢子单核体自交后代作双核体亲本,与相应的孢子单核体进行半亲和双单杂交,得到6个杂交后代,均具有结实能力,说明半亲和双单杂交后代可以用于育种研究。大多数杂交菌株(核基因相同)在菌丝生长速率与CMC酶活方面显示出不同程度遗传差异,其中3号与4号菌株在菌丝生长速率与CMC酶活方面呈现明显杂种优势。     

酯酶同工酶及RAPD技术在香菇杂种优势研究中的应用

采用酯酶同工酶及RAPD技术对香菇3个亲本双核体(苏香、野生46#、野生80#)及其10个单核体、以及它们的10个杂交后代进行了遗传差异和亲缘关系的研究,同时针对亲本单核体酯酶同工酶标记和RAPD标记遗传距离、以及杂交子和亲本单核体RAPD标记遗传距离与香菇产量超亲优势进行了相关性分析。结果表明,酯酶同工酶和RAPD技术都可进行香菇杂种优势群的划分研究,但RAPD标记检测的多态性要远远高于酯酶同工酶标记。相关分析结果表明,亲本单核体酯酶同工酶标记遗传距离与香菇产量超亲优势无相关性,而RAPD标记遗传距离与其存在极显著正相关;杂交子和以苏香为来源的单核体亲本之间RAPD标记遗传距离与香菇产量超亲优势也存在极显著正相关,而杂交子和以野生46#、野生80#为来源的单核体亲本之间RAPD标记遗传距离与其相关不显著。     

酯酶同工酶及RAPD技术在香菇杂种优势研究中的应用*

采用酯酶同工酶及RAPD技术对香菇3个亲本双核体(苏香、野生46#、野生80#)及其10个单核体、以及它们的10个杂交后代进行了遗传差异和亲缘关系的研究,同时针对亲本单核体酯酶同工酶标记和RAPD标记遗传距离、以及杂交子和亲本单核体RAPD标记遗传距离与香菇产量超亲优势进行了相关性分析。结果表明,酯酶同工酶和RAPD技术都可进行香菇杂种优势群的划分研究,但RAPD标记检测的多态性要远远高于酯酶同工酶标记。相关分析结果表明,亲本单核体酯酶同工酶标记遗传距离与香菇产量超亲优势无相关性,而RAPD标记遗传距离与其存在极显著正相关;杂交子和以苏香为来源的单核体亲本之间RAPD标记遗传距离与香菇产量超亲优势也存在极显著正相关,而杂交子和以野生46#、野生80#为来源的单核体亲本之间RAPD标记遗传距离与其相关不显著。     

酯酶同工酶及RAPD技术在香菇杂种优势研究中的应用

采用酯酶同工酶及RAPD技术对香菇3个亲本双核体(苏香、野生46^#、野生80^#)及其10个单核体、以及它们的10个杂交后代进行了遗传差异和亲缘关系的研究,同时针对亲本单核体酯酶同工酶标记和RAPD标记遗传距离、以及杂交子和亲本单核体RAPD标记遗传距离与香菇产量超亲优势进行了相关性分析。结果表明,酯酶同工酶和RAPD技术都可进行香菇杂种优势群的划分研究,但RAPD标记检测的多态性要远远高于酯酶同工酶标记。相关分析结果表明,亲本单核体酯酶同工酶标记遗传距离与香菇产量超亲优势无相关性,而RAPD标记遗传距离与其存在极显著正相关;杂交子和以苏香为来源的单核体亲本之间RAPD标记遗传距离与香菇产量超亲优势也存在极显著正相关,而杂交子和以野生46^#、野生80^#为来源的单核体亲本之间RAPD标记遗传距离与其相关不显著。     

香菇正反双单杂交后代的遗传分析*

选用香菇的杂交菌株农１与野生株Ｑ进行正反双单杂交,得到６个杂交后代。结果表 明：３个正交菌株与３个反交菌株在酯酶同工酶与ＤＮＡ水平上具有极高的相似性,而对杀菌 剂和温度的敏感性显示了明显的遗传差异,且农艺性状遗传差异也十分显著。正反杂交菌株在 核基因相同情况下的遗传差异应主要归于细胞质差异。本研究表明,香菇双单杂交后代是同质 异核体。     

利用RAPD技术检测香菇双-单杂交后代

利用ＲＡＰＤ技术对香菇６个双单杂交菌株及其两个双核体基因组ＤＮＡ进行了检测,结果显示：１～３号杂交菌株之间的相似系数为０．８９３～０．９６２,它们与其亲本Ｓ之间的相似系数为０．８４２～０．８５９;４～６号杂交菌株之间的相似系数０．８５７～０．９２５,与其亲本ＳＳＯ１之间相似系数为０．７０８～０．９０２表明杂交菌株与其双核体亲本基因组具有较大差异,杂交菌株之间存在着不同程度差异,６个杂交菌株是真正的杂交后代,聚类分析树状图直观地表明了菌株间的遗传相关性,认为菌株间ＤＮＡ的相似系数值可以作为杂交育种选择亲本的     

香菇正反双单杂交后代的遗传分析

选用香菇的杂交菌株农1与野生株Q进行正反双单杂交,得到6个杂交后代。结果表明：3个正交菌株与3个反交菌株在酯酶同工梅与DNA水平上具有极高的相似性,而对杀菌剂和温度的敏感性显示了明显的遗传差异,且农艺性状遗传差异也十分显著。正反杂交菌株在核基因相同情况下的遗传差异应主要归于细胞质差异。本研究表明,香菇双单杂交后代是同质异核体。     

6个杏鲍菇菌株生理生化研究

目的:对收集的6个杏鲍菇菌种菌丝进行生理、生化研究,酯酶同工酶法分析菌株间的差异与关系。方法:利用杏鲍菇菌丝阶段的生长速度测定、诱变剂抗性试验和酯酶同工酶比较,对杏鲍菇菌株营养生长阶段的理化指标进行研究,对酯酶同工酶谱进行相似系数和遗传距离分析,确立各菌株的异同。结果:菌株间菌丝生长速度差异不显著;抗诱变剂实验结果显示,2、5、6号菌株对诱变剂抗性较强;酯酶同工酶分析表明,杏鲍菇6个菌株同工酶酶带存在的差异很大。结论:通过试验表明,所选6株杏鲍菇菌种为各自独立菌株。     

两种虫生真菌酯酶同工酶酶谱多样性研究

采用聚丙烯酰胺凝胶电泳技术对不同来源的22株球孢白僵菌和21株粉拟青霉酯酶同工酶的酶谱多样性进行了研究,由酯酶图谱可知同种不同菌株间具有丰富的遗传多样性,可作为菌株亲缘关系的可靠的遗传标记。遗传距离进行聚类分析,结果表明球孢白僵菌、粉拟青霉不同菌株间亲缘关系的远近与寄主范围无任何相关性,与菌株来源地在某些菌株间存在一定的相关性。     

利用RAPD技术检测香菇双—单杂交后代

利用ＲＡＰＤ技术对香菇６个双单杂交菌株及其两个双核体基因组ＤＮＡ进行了检测,结果显示：１－３号杂交菌株之间的相似系数为０．８９３－０．９６２,它们与其亲本Ｓ之间的相似系数为０．８４２－０．８５９;４－６号杂交菌株之间的相似系数０．８５７－０．９２５,与其亲本ＳＳＯ１之间相似系数为０．７０８－０．９０２;表明杂交菌株与其双核体亲本基因组具有较大差异,杂交菌株之间存在着不同程度差异,６个杂交菌株是真正     

Breeding and identification of novel koji molds with high activity of acid protease by genome recombination between <Emphasis Type="Italic">Aspergillus oryzae</Emphasis> and <Emphasis Type="Italic">Aspergillus niger</Emphasis>

Acid protease is essential for degradation of proteins during soy sauce fermentation. To breed more suitable koji molds with high activity of acid protease, interspecific genome recombination between A. oryzae and A. niger was performed. Through stabilization with d-camphor and haploidization with benomyl, several stable fusants with higher activity of acid protease were obtained, showing different degrees of improvement in acid protease activity compared with the parental strain A. oryzae. In addition, analyses of mycelial morphology, expression profiles of extracellular proteins, esterase isoenzyme profiles, and random amplified polymorphic DNA (RAPD) were applied to identify the fusants through their phenotypic and genetic relationships. Morphology analysis of the mycelial shape of fusants indicated a phenotype intermediate between A. oryzae and A. niger. The profiles of extracellular proteins and esterase isoenzyme electrophoresis showed the occurrence of genome recombination during or after protoplast fusion. The dendrogram constructed from RAPD data revealed great heterogeneity, and genetic dissimilarity indices showed there were considerable differences between the fusants and their parental strains. This investigation suggests that genome recombination is a powerful tool for improvement of food-grade industrial strains. Furthermore, the presented strain improvement procedure will be applicable for widespread use for other industrial strains.     

Mating speed differences between Australian populations ofDrosophila melanogaster

Mating speeds have been studied for two natural populations ofDrosophila melanogaster collected in Victoria, Australia, about 100 miles apart. Significant differences in mating speed were found and hybrids between the populations gave intermediate mating speeds. A small difference between strains in duration of copulation was found.The differences in mating speeds were controlled by the strain of the male, the strain of the female having little effect. No appreciable behavioural interactions were found between strains.     

A Flow Cytometric Method for Rapid Selection of Novel Industrial Yeast Hybrids

We rapidly produced and isolated novel yeast hybrids by using two-color flow cytometric cell sorting. We labeled one parent strain with a fluorescent green stain and the other parent with a fluorescent orange stain, and hybrids were selected based on their dual orange and green fluorescence. When this technique was applied to the production of hybrids by traditional mating procedures, more than 96% of the isolates were hybrids. When it was applied to rare mating, three hybrids were identified among 50 isolates enriched from a population containing 2 × 10⁶ cells. This technology is not dependent on genetic markers and has applications in the development of improved industrial yeast strains.     

Electrophoretic analysis of soluble proteins and esterase, superoxide dismutase and acid phosphatase isoenzymes of members of the protozoan family trichomonadidae

Polyacrylamide gel electrophoresis was used to compare the proteins and isoenzymes of esterase, superoxide dismutase, and acid phosphatase in soluble, whole-cell extracts of four strains of Trichomonas vaginalis, two strains of Trichomonas gallinae, and one strain each of Tritrichomonas foetus, Tritrichomonas augusta, Tetratrichomonas gallinarum, and Pentatrichomonas hominis. Intraspecific, interspecific, and intergeneric differences were found in protein and isoenzyme profiles. At least four to seven isoenzymes were detected among the ten strains for each of the three enzymes studied. Each strain usually contained one or two isoenzymes of both esterase and acid phosphatase, and two or three isoenzymes of superoxide dismutase.     

Conversion of Wine Strains of Saccharomyces cerevisiae to Heterothallism

A general method to convert homothallic strains of the yeast Saccharomyces cerevisiae to heterothallism is described which is applicable to genetically well-behaved diploids, as well as to strains that sporulate poorly or produce few viable and mating-competent spores. The heterothallic (ho) allele was introduced into three widely used wine strains through spore × cell hybridization. The resultant hybrids were sporulated, and heterothallic segregants were isolated for use in successive backcrosses. Heterothallic progeny of opposite mating type and monosomic for chromosome III produced by sixth-backcross hybrids or their progeny were mated together to reconstruct heterothallic derivatives of the wine strain parents. A helpful prerequisite to the introduction of ho was genetic purification of the parental strains based on repeated cycles of sporulation, ascus dissection, and clonal selection. A positive selection to isolate laboratory-wine strain hybrids requiring no prior genetic alteration of the industrial strains, coupled with a partial selection to reduce the number of spore progeny needed to be screened to isolate heterothallic segregants of the proper genotype made the procedure valuable for genetically intractable strains. Trial grape juice fermentations indicated that introduction of ho had no deleterious effect on fermentation behavior.     

Apparent bisexual behavior of yeast strains obtained from hybridization of industrial yeasts of the genusSaccharomyces with auxotrophic diploids

During a genetic study of some hybrids of brewer's and distiller's yeast strains with impaired sporulation characteristics and genetically marked auxotrophic aa and alpha alpha diploids, strains which showed positive mating reactions with both a and alpha haploid tester strains were observed. These strains proved to be homothallic and sporulated freely. The original hybrids, which appeared to be tetraploid, usually yielded sporulating single-spore clones on dissection of asci formed from them, with few or no mating strains among them. Dissection of asci from these clones yielded some single-spore clones which showed mating reactions with one or the other or both haploid tester strains, and further selection produced strains which on sporulation and dissection yielded single-spore clones which were apparently bisexual and sporulated freely. These strains proved to be homothallic, yielding single-spore clones which were all of the a mating type, and in which the mating reaction and, possibly, the action of the genes for homothallism were impaired, so that sporulating, non-mating diploids and haploids of both mating types were present in cultures originally obtained as single-spore clones.