紫珍香葡萄自交后代对霜霉病抗性鉴定及叶片相关生化指标分析

在葡萄霜霉病盛发期,通过田间自然鉴定和对感病前后叶片中PPO、PAL的活性进行测定,研究紫珍香自交后代的6个株系对霜霉病的抗性。结果表明:PPO、PAL 2个防御酶活性与供试葡萄抗性间存在正相关,6个供试株系对霜霉病的抗性存在显著差异,其中08-88的抗性最强,显著高于抗病亲本紫珍香;08-420、8-51的抗病性中等;08-1410、8-960、8-13的抗病性最弱,且显著低于对照。     

黑木耳白色品种的选育

将收集到的黑木耳(Auricularia heimuer)白色变异菌株进行分离、纯化和栽培,选择性状理想的纯白色菌株,收集孢子,经自交纯合,获得稳定遗传的纯白色黑木耳菌株JAUH-W-591。通过形态学观察,结合分子生物学分析方法对该菌株进行鉴定,确定其为黑木耳的白色变种。实验表明,JAUH-W-591菌丝生长的最适碳源为乳糖,最适氮源为酵母浸粉,最适培养温度为25~28 ℃,最适pH为6.5。生产实验结果表明:新品种JAUH-W-591的平均产量为每袋干重53.5 g,较对照平均增产7.1%,具有较明显的商品优势和栽培价值。     

梨花柱S糖蛋白对离体花粉萌发及花粉管生长的影响

应用CM和SP琼脂糖凝胶 (Sepharose)离子交换层析法从‘新水’梨花柱可溶性蛋白质中分离纯化出具有RNase活性的S糖蛋白 ,将其加入花粉培养基 3～ 12h ,新水花粉 (自交不亲和 )的萌发率及花粉管生长受到强烈抑制 ,当浓度为 1.2 5μg·μL- 1时 ,分别为对照的 6 5%和 38% ,低浓度 (0 .4 μg·μL- 1)抑制作用不明显 ;与新水杂交不亲和的‘幸水’花粉也出现同样的结果 ;而与其杂交亲和的‘长十郎’花粉萌发率不受影响 ,仅花粉管生长受到轻微的抑制 ,其长度为对照的 79%。不含S糖蛋白的花柱可溶性蛋白质对自花及异花的花粉萌发及花粉管生长均无影响。     

梨自花及异花授粉对其花柱自发荧光的影响

 利用激光共聚焦显微技术研究了砂梨(Pyrus serotina Rehd．)品种‘丰水’ 自花授粉和异花(‘二十世纪’)授粉16 h后花柱自发荧光的分布规律。发现未授粉花柱整体的自发荧光比较弱。但从柱头端向子房端花柱自发荧光呈上升趋势;异花授粉和自花授粉后花柱整体的自发荧光都有所增加;授粉后自发荧光变化最大的部位在柱头区域; 自花授粉后,在柱头及距柱头0～400an范围内荧光值较高,其他区域的荧光值相近;而异花授粉后在花柱的中部(距柱头1500～2050an范围内)荧光值最低; 自花授粉后自发荧光除柱头以外主要分布在花柱的边缘区域;异花授粉后自发荧光在花柱上半部的分布情况与自花授粉类似,下半部分布相对均匀。关键词：中图分类号： 文     

紫薇属与散沫花属远缘杂交亲和性的研究

以紫薇属的紫薇（Lagerstroemia indica）品种‘Bicolor’、‘XTSC3’和尾叶紫薇（L. caudata）分别与散沫花属的散沫花（Lawsonia inermis）进行远缘杂交,对杂交亲本的花粉和柱头进行了扫描电镜观察,并对授粉后花粉萌发及花粉管伸长过程进行荧光显微观察。结果表明,紫薇属与散沫花属杂交存在受精前障碍。散沫花的花粉可以在紫薇品种‘Bicolor’、‘XTSC3’和尾叶紫薇柱头上萌发,但花粉萌发滞后,花粉管的伸长受到阻碍,难以在72 ~ 96 h内伸入子房完成受精。而散沫花作母本时,不亲和性表现为花粉与柱头间在形态上不匹配,柱头上花粉粒粘附少,柱头胼胝质的生成阻碍了花粉萌发。     

Inheritance of stylar ribonucleases in cherry progenies, and reassignment of incompatibility alleles to two incompatibility groups

Stylar proteins were extracted from parents and seedlings of six progenies of cherry (Prunus avium), separated using isoelectric focusing, and the gels stained for ribonuclease activity. The zymogram of each plant showed two main ribonuclease bands in the region pI 8.3 to 9.6. Progenies from crosses of parents with one band in common segregated into just two classes, whereas progenies from crosses of parents with no common bands segregated into four classes, the two types of segregation corresponding to those expected from semi-compatible and fully-compatible crosses respectively. This behaviour was consistent either with the ribonuclease locus being tightly linked with the self-incompatibility, S, locus, or else with the S locus coding for the ribonuclease variants. Evidence favouring the latter hypothesis is discussed. An apparently anomalous segregation led us to assign to ‘Bradbourne Black’ a genotype different from that previously reported, and analysis of some other cultivars in the same incompatibility group, Group VII, led us to conclude the genotype of this group is S₃S₅, and not S₄S₅ as previously reported. Correspondingly, we suggest the genotype of Group V is S₄S₅, and not S₃S₅. Five new S alleles, S₇, S₈, S₉, S₁₀ and S₁₁ were proposed in parental cultivars and selections that had not previously been assigned a genotype. This revised version was published online in July 2006 with corrections to the Cover Date.     

Mechanism of seedlessness in Iranian seedless barberry (Berberis vulgaris L. var. asperma)

Species of barberry (Berberis vulgaris L. var. asperma) is cultivated in arid and semi arid areas of Iran (South Khorasan province). It is widely used as a food additive. Fruits of this species are seedless, while wild type barberries produce seeds in the same area. In this study, we investigated the mechanism of seedlessness in seedless barberry by pollen viability test, field pollination experiments and microscopic observation of pollen tube growth in pistil and ovule development. For comparison, we also examined ovule development in wild type barberry (B. crataegina DC). In seedless barberry pollen germination was about 54%. Seedless barberry produced 20% seeded fruits when pollinated with pollen of wild type barberry. There was a sharp decrease in fruit set in emasculated unpollinated flowers of seedless barberry. In seedless barberry, a large number of pollen grains (about 370) were observed on stigma of each flower at 12 h after balloon stage (ABS). Most of them germinated and penetrated intracellular area of stigma surface, but no pollen tube reached ovary. In seedless barberry, many ovules did not have any embryo sac or had a very small incomplete embryo sac. In addition, unfused polar nuclei were clearly recognized in some cases at 14 days after full bloom (AFB). However, in wild type, double fertilization was accompanied by disappearance of polar nuclei. In seeded barberry, the cellularized endosperm became apparent at seven days AFB. At 21 days AFB, all ovules of seedless barberry were degenerated, while at the same time in wild type, one or two ovules of each flower were normal and were developing into complete seeds. Results showed that self-incompatibility has a main role in seedlessness of seedless barberry. However, the high frequency of abnormal ovules and single fertilization can be considered as two other reasons of seedlessness. Due to our results, fruits of seedless barberry were set by stimulative parthenocarpy.     

Different breeding systems of three varieties of Bidens pilosa in Taiwan

Three varieties of the introduced Bidens pilosa (Hairy beggar‐ticks; Asteraceae) co‐exist in Taiwan. Bidens pilosa var. minor and var. pilosa are naturalised, while only var. radiata is invasive. Differences in seed set in bagged versus open‐pollinated capitula, pollen–pistil interactions and the pollen/ovule (P/O) ratio were investigated among these three varieties. In contrast with the resulting 45–55% seed set in each bagged capitulum of var. minor and var. pilosa, almost no mature seeds (1–2 seeds) were found in bagged capitula of var. radiata, showing that var. radiata has a low capability of autonomous seed production. In bagged capitula, only 1.5% of pistils of var. radiata, but 76% and 52% of those of var. minor and pilosa, respectively, had pollen tubes penetrating into their styles, suggesting that var. radiata has strong self‐incompatibility mechanisms preventing autonomous autogamy. The P/O ratio, with mean values of 8189, 2053 and 1613 for var. radiata, var. minor and var. pilosa, respectively, were counted. These results support the hypothesis that the three varieties bear different breeding systems; the invasive var. radiata is highly self‐incompatible, whereas the other two naturalised varieties are self‐compatible.     

Altered Phenotypic Response to Peronospora parasitica in Brassica juncea Seedlings Following Prior Inoculation with an Avirulent or Virulent Isolate of Albugo candida

A study was made of the biological interactions between an isolate of Peronospora parasitica compatible with Brassica juncea and two isolates of Albugo candida either incompatible or compatible with the host species. Prior inoculation with the incompatible isolate of A. candida induced resistance to subsequently inoculated P. parasitica. The degree of resistance was proportional to the zoosporangia concentration of the incompatible isolate and induced resistance was more marked in the cotyledon receiving the inducing inoculum compared to the opposite cotyledon and subsequently emerging true leaves that had not been pre-inoculated. Induction of resistance was also observed if the incompatible isolate of A. candida and P. parasitica were co-inoculated simultaneously. However, the effect was greater the longer the interval between inoculations, up to a period of 4 days. When the incompatible isolate of A. candida was inoculated 4h after P. parasitica, there was no marked effect on resistance to the latter. In contrast, prior inoculation with the compatible isolate of A. candida increased susceptibility to P. parasitica inoculated subsequently. However, pre- or co-inoculation with P. parasitica suppressed the development of the compatible isolate of A. candida. A spectrum of responses was observed when one cotyledon was inoculated simultaneously with both the incompatible and compatible isolates of A. candida and followed subsequently with P. parasitica after different time intervals. In such combinations, a transition was observed in the host response to P. parasitica from induced resistance/reduced susceptibility, which increased up to 24h following a simultaneous inoculation with incompatible + compatible isolates of A. candida to an almost neutral reaction after 72h to induced susceptibility after 96h. This range of altered responses appeared to reflect the outcome of the differing kinetics and counter-effects of resistance and susceptibility induction.     

Genotyping apricot cultivars for self-(in)compatibility by means of RNases associated with S alleles

In previous work the existence of proteins with RNase activity associated with S alleles in apricot was demonstrated. These proteins were inherited as described previously for the inheritance of self‐compatibility in this species. In this study, new cultivars have been genotyped for self‐compatibility using this method and it has been demonstrated that in all self‐compatible cultivars examined, the self‐compatibility allele is the same and is associated with an RNase with high activity. Homozygous self‐compatible individuals have been detected among established cultivars as well as among seedlings following breeding activity. This germplasm is of great value within the breeding programme because only self‐compatible seedlings will be produced. The number of S alleles in apricot appears to be low and only eight different alleles have been found in the large number of different cultivars screened. Furthermore, there are alleles present in the Spanish population that are also found in the genetic pool of North American cultivars. The screening of a progeny from the cross between the American cultivar ‘Goldrich’ and the Spanish cultivar ‘Pepito’ demonstrated the existence of the common allele S₂ (detected previously by examining RNases), which was confirmed by the segregation of self‐compatibility in the progeny.