Morphological and isozyme variation in genebank accessionsof Aegilops umbellulata Zhuk., a wild relative of wheat

Morphological variation and genetic variation at 15 enzyme lociwere studied in genebank accessions of Aegilopsumbellulata Zhuk., the diploid genome donor to all thepolyploid species of the section Aegilops ofAegilops. Accessions from the Greek Islands hadshorter spikes with smaller number of spikelets and smaller number ofawns on the empty glume. The number of alleles per locus (A= 2.01) and the proportion of polymorphic loci (P= 0.627) were similar to those of the other species ofAegilops so far reported. Genetic distancescalculated from isozyme variations among five regions revealed thataccessions from the Greek Islands are more distantly related to theother four continental regions, Iran and Iraq, Southeast Turkey,Central Turkey and South and West Turkey. The present resultsindicated the importance of collection covering the whole range ofgeographical distribution to capture the genetic variation present inAe. umbellulata.     

Application of Isozyme Data in Fingerprinting Napier Grass (Pennisetum purpureum Schum.) for Germplasm Management

Sixty-four accessions of Napier grass (Pennisetum purpureum Schum.), a forage crop of tropics and subtropics, were assessed for polymorphism in isozymes and total proteins (TP). The national germplasm collection exhibited polymorphism in all the three isozymes viz., malate dehydrogenase, glutamate oxaloacetate transaminase and peroxidase (POX) besides TP profile. Though POX and TP showed comparatively higher polymorphism, the study indicated the efficiency of three-enzyme system in identifying more than 90% of the accessions. The combination of TP and three-enzyme systems provided unique isozyme/TP banding patterns for all the 64 accessions leading to development of accession specific profile/fingerprints. In Napier, which is perennial with long vegetative phase, it is difficult to discriminate germplasm accessions based only on morphology. Thus biochemical markers could be efficiently utilized to complement morphological evaluations, in maintaining identity and purity of germplasm for proper conservation and management, for better use in breeding and for proprietary reasons.     

Isozyme Polymorphism and Genetic Differentiation in Natural Populations of a New Tetraploid Species <Emphasis Type="Italic">Avena agadiriana</Emphasis>, from Morocco

A new wild tetraploid oat Avena agadiriana Baum et Fedak was collected from the five populations along the Atlantic coast in Morocco. Variations in six enzyme systems were surveyed and allele frequency, percentage of polymorphic loci, number of alleles per locus, observed and expected heterozygosities, and unbiased genetic distance were calculated. Phenotypic frequencies were scored representing 11 polymorphic loci. The mean percentage of polymorphic loci was 46.25, the mean number of alleles per locus was 1.502, and the mean expected heterozygosity was 0.1526. Two heterozygotes resulting from outcrosses were found in the progeny from M60 and M71. The population of M71 had peculiar alleles Est-4A not present in the other populations. Most of the genetic diversity of this species was between populations with little existing within populations. Geographic and genetic distances between populations were positively correlated with each other and the correlation coefficient was 0.7031. Cluster analysis showed two strongly differentiated groups were apparent, M71 and M74, and the remainder. The former group appears to be adapted to man-made habitat, such as road side or eucalyptus plantation, and the latter to a distinct dry, sandy habitat. To make wide intra-specific variation in this species, the modified mating system would be indispensable.     

Maturity and cooling rate affects browning,polyphenol oxidase activity and gene expression of ‘Yali’ pears during storage

Browning is the main physiological disorder of ‘Yali’ pear (Pyrus bretschneideri Rehd) during storage. In this study, the relationships between browning development in fruit from different harvest dates, and cooled either rapidly or slowly, with polyphenol oxidase (PPO) activity and isozymes, and PPO gene expression has been investigated. Development of browning was highest in late-harvest fruit in both core and flesh tissues and was higher in rapidly cooled than slowly cooled fruit. Mid-harvest fruit had the lowest browning incidence and PPO activity of core tissue was higher than in flesh and seeds, while the peak of PPO activity in mid-harvest fruit was the lowest. Six PPO isoenzymes were detected in fruit, three bands A, B and E in flesh and core tissues, three bands C, D and F in the seeds. The intensity of PPO isoenzyme staining of bands A and B in pulp and core was similar to that of PPO activity and browning incidence. PPO gene expression increased and then decreased in core tissues. Trends of expression were similar to those of PPO activity. Rapid cooling promoted the expression PPO. The results suggest PPO plays an important role in ‘Yali’ pear browning during storage.     

黄,白金针菇品系酯酶同工酶标记筛选研究初报

采用垂直平板聚丙烯酰胺凝胶电泳,研究不同生长发育期、不同组织对金针菇[Fla~(?)mmulina velutipes(Fr.)Kar.]黄、白品系酯酶同工酶电泳表型的影响,筛选出不受生长发育期及常规培养条件影响的酯酶标记区带.标记区带分基本带和识别带.酯酶同工酶标记区带电泳表型显示出多态型.利用酯酶同工酶标记区带分析黄、白金针菇酶谱差异,显示出黄、白金针菇品系有共同的遗传基础.     

三角城藏羊红细胞乳酸脱氢酶同工酶酶谱

采用聚丙烯酰胺凝胶电泳(PAGE)法对83只三角城藏羊的红细胞乳酸脱氢酶(LDH)同工酶酶谱进行分析。结果发现:①红细胞LDH同工酶总共有11条区带;②第1区带的电泳迁移率为54.3％,第11区带的电泳迁移率为25.0％;③红细胞LDH有两种电泳表型,78只羊为LDHⅠ型,占93.98％,5只羊为LDHⅡ型,占6.02％。     

猪和绵羊组织器官乳酸脱氢酶同工酶酶谱比较

应用聚丙烯酰胺凝胶电泳法对猪和绵羊的心、肝、脾、肺、肾、胰、小肠７种组织器官及血清的乳酸脱氢酶同工酶酶谱进行比较研究，结果发现：①猪和绵羊各组织器官中ＬＤＨ同工酶共有５种区带，猪的ＬＤＨ３同工酶还可分为两条亚带；②猪和绵羊的肺、肾、小肠、胰、血清中ＬＤＨ区带数相同，其它组织器官各不相同；③猪和绵羊ＬＤＨ１同工酶的泳动速度最快，迁移率分别为５３．６４％、４１．８２％；ＬＤＨ５同工酶的泳动速度最慢，迁     

大豆疫霉菌与其它几种疫霉菌同工酶电泳比较研究

本对大豆疫霉菌（Phytophthora sojae）的15个菌株及其它7种疫霉的8个菌株进行了4种同工梅电泳比较研究。结果表明，大豆疫霉菌种内菌株间4种同工酶基本一致。疫霉属种间酯酶（EST）和超氧化物歧化酶（SOD）酶谱存在明显差异，表现为酶带的多少和Rf值的不同；淀粉酶（DIA）和过氧化氢酶（CAT）同工酶酶谱差异不很明显，与某些疫霉种酶谱相似，只表现为酶带强度上的差异。本首次报道了大豆疫霉菌的SOD、CAT和DIA同工酶，并指出EST和SOD同工酶在P.sojae种的鉴定上具有重要意义，在P.sojae种的鉴定提供一个辅助性手段。     

豇豆属内栽培种分类的再研究

 通过豇豆属、菜豆属6个豆种的148份材料的20个重要形态性状的观察，过氧化物酶、酯酶同工酶的比较分析，应用数值分类法对豇豆属栽培种的分类及亲缘关系进行了研究。 6个豆种的形态聚类为黑吉豆、绿豆、饭豆类群；豇豆类群；菜豆类群；过氧化物酶酶谱聚类为绿豆、黑吉豆、饭豆类群；小豆类群；豇豆类群；菜豆类群。酯酶酶带扫描峰聚类为小豆、饭豆类群、绿豆、黑吉豆类群；豇豆类群和菜豆类群。 据上述结果认为：⑴将绿豆、黑吉豆、饭豆、小豆从菜豆属划出更符合生物自身的自然属性；⑵绿豆等4个豆种与豇豆种在许多性状、同工酶表现上存在较大差异，是否将其归入豇豆属值得重新考虑；⑶绿豆与黑吉豆、小豆与饭豆间的亲缘关系最近，而饭豆与绿豆、黑吉豆较小豆与之具有更近的亲缘关系。     

添加圆葱寡糖对肉鸡代谢功能调控的研究

在肉鸡饲粮中添加圆葱寡糖(1.5％),对山东地方特色保种白羽鸡进行饲养试验,用聚丙烯酰胺凝胶电泳(SDS)PAGE技术,分析血液中酯酶(EST)、乳酸脱氢酶(LDH)、蛋白质的多态。结果表明,试验组蛋白结构新出现>100Ku亚基组分,存在多态变化。EST同工酶快区Es-1位点,由多等位基因控制,酶带着色程度显著减弱,其活性下降45.8％,LDH同工酶出现4条酶谱带,酶带着色的程度明显增强,其活性增加2.5倍。提示圆葱寡糖直接或间接影响基因表达水平,调控生化生理代谢功能。