Investigation on pre-zygotic barriers in the interspecific crosses involving Gossypium barbadense and four diploid wild species

Interspecific hybridisation has played significant role in the improvement of economically useful traits such as productivity, earliness, fibre quality and resistance to pests and diseases in cotton. However, wide crosses are often limited by the operation of either pre or/and post-fertilization barriers. The present study on pollen tube behaviour of four diploid wild species viz., G. triphyllum, G. davidsonii, G. thurberi and G. armourianum in the pistils of G. barbadense was taken up to determine the extent of pre-zygotic barriers operating in these crosses. High rate of pollen germination (∼80%) and normal growth of pollen tubes were observed upon selfing of both G. barbadense and four wild species. Pollen tubes reached the pistils and fertilization was accomplished within 8 HAP in all the five parental species. In the interspecific crosses, pollen germination was normal in the cross involving G. armourianum and drastically inhibited in the crosses involving G. triphyllum, G. davidsonii and G. thurberi. Even though delayed pollen tube growth was a general feature in all the four crosses, successful fertilization was observed only in the cross involving G. armourianum. In crosses involving G. triphyllum, G. davidsonii and G. thurberi, pollen tubes failed to reach the ovary even at 24 HAP due to the presence of strong stylar and ovarian incompatibility. Abnormalities in pollen tubes such as swelling, twisting, intense callose plug formation, breakage, branching and reverse orientation were frequently observed among the incompatible crosses.     

Molecular and physiological identification of new S-alleles associated with self-(in)compatibility in local Spanish almond cultivars

The S-allele characterisation of ‘Alzina’ and ‘Garondès’, two local almond cultivars from the island of Majorca, by a multidimensional approach has allowed the confirmation of the presence of the S_f-allele and the identification of a new allele not previously described in almond, S₃₆. When these cultivars were phenotypically evaluated, both showed a self-incompatible phenotype and were cross-incompatible, as assessed by artificial self- and cross-pollinations and fruit sets after field pollinations, confirming that their S_f-allele is in its active form, S_fa. Thus a new CGI group in almond is proposed and named XXVIII. These results confirm the wide diversity of S-alleles in almond both at genotypic and phenotypic levels, as well as their similarity with the S-alleles from other close Prunus species. This similarity suggests the possibility of allele introgression between species or allele identity by descent from a common ancestor.     

梨花柱半离体培养法及品种自交不亲和基因型鉴定

 ：切取梨授粉花柱进行半离体培养的结果表明，杂交不亲和性组合从花柱基部长出花粉管的花柱比率为0～32．4％ ，且大多在16％ 以下，而杂交亲和性组合为51．6％ ～86．7％ ，与田间杂交授粉的坐果率相近，且在授粉花粉的萌发率达20％以上时，温室水培枝条促成的花与露地开花的花之间没有显著差异。应用此方法鉴定出了梨品种‘筑水’、‘喜水’及‘爱甘水’的s基因型分别为s s 、s s 、及s s 。     

广东甘薯品种资源杂交不亲和群的鉴定及分析研究

 自1981-1986年6年期间利用广东省丰富的甘薯品种资源及其有利于自然开花的气候条件，测定出313个品种的杂交不亲和群的群别，其中属B群品种资源的最多。按不同群别品种数目多少排列，其顺序是B群＞A群＞D群＞C群＞A#-1-2群＞美国红群＞铁线藤群。同时测出7群外品种6个，半亲和群品种17个，分属B、D、美国红群，而其中有7个属多群性半亲和品种。对甘薯杂交育种亲本组配中确定群别因素和提高杂交结实率，以及对不亲和性的研究，提供大量基础资料。经研究分析指出：⒈在广州利用天然开花条件开展测群工作，宜于10-11月下旬的上半旬；⒉可以应用地方性的农家品种资源群别鉴定资料及其地理分布状况，推断甘薯的传播途径，为农业考古提供科学依据；⒊通过杂交不亲和性鉴定可以作为整理甘薯品种资源的辅助手段。     

Pollen pistil interactions and interspecific incompatibility in Pennisetum

Summary The causes of low crossability between Pennisetum species were studied. In the compatible cross P. typhoides x P. violaceum, the pollen tube growth was normal and there was good seed set. In P. typhoides x P. cenchroides, pollen tubes reached the ovary but no seed set was obtained indicating ovarian incompatibility. The stylar incompatibility was found in the crosses of P. typhoides with P. schweinfurthii, P. hohenackeri, P. orientale and P. squamulatum. In crosses P. typhoides x P. polystachyon and P. typhoides x P. pedicellatum, mostly pollen tubes did not grow beyond stigmatic surface and only few reached the style. Stigmatic as well as stylar incompatibilities seem to be the reasons for no seed set in these crosses.     

玉米杂交不亲和性研究初探

利用国内发现的玉米杂交不亲和性材料Inco.1进行了正反交测交和回交试验 ,表明它不能接受除爆裂玉米外的任何一类玉米的花粉 ,因而果穗不结子 ,相反用它的花粉授到各类玉米花粉上 ,则能正常结子 ,说明它是一个单向杂交不亲和性材料 ,具有较强的花粉竞争优势 ,是由显性配子体基因Ga^s 控制的 ,这与国外认为所有的马齿玉米为ga因子控制的论点完全不同 ,是一个值得重视的遗传材料。应用回交方法可以转育这种特性到其他类型的玉米上。     

盐溶蛋白电泳鉴定玉米异交不亲和性的研究

采用聚丙烯酰胺凝胶电泳对六个玉米异交不亲和系的盐溶蛋白进行了初步研究,共有2~3条玉米异交不亲和性的盐溶蛋白谱带可作为今后玉米异交不亲和性性状鉴定的依据,其分别位于B区的Rf=25.8、Rf=47.8和D区中Rf=78.8位置上,且谱带清晰明朗。结果表明：盐溶蛋白电泳可以用来鉴定玉米异交不亲和性。     

甘薯杂交不亲和群的鉴定分析及在育种上的应用

先后对365个甘薯品种、品种资源进行了鉴定,使甘薯的群别类型由8个增加到13个,并且使A、B、C三群所占比例由原来的78.42%下降到72.70%,扩大了三群之外群别的品种数量,丰富了亲本材料的遗传基础,提高了育种效率,并选育出烟薯16号、鲁薯3号、烟薯8号、鲁薯6号、烟27、烟薯406等一批优良的品种(系)。