New sexual approaches to transfer of genes in wide crosses.

1)印度小组的主要目标是开发芥菜的遗传改良方法。(1)通过胚挽救培养，已经产生了20多个野生种和不同栽培种之间的属间杂种。也曾试图实现体外受精，以克服受精前的障碍，但没有成功。具有Siifolia细胞质背景的芥菜型油菜（B.juncea）细胞质雄性不育系已发展到晚期（Shivanna）。(2)芥菜型油菜（B.juncea）雄激素诱导胚的产生率极低，花粉胚不能正常萌发。由于对供体植物的条件和组织培养方法进行了改进，花粉胚已变得能够高效率地萌发。此外，还对花粉胚的转化进行了初步尝试。在东京大学（Bhojwani）将负载在金颗粒上的构建体pBI 121轰击到花粉胚中。2）日本小组研究开发了不同于印度小组的新技术。(1)当多聚鸟氨酸的方法应用于烟草的离体授粉时，证实了花粉管中的瞬时GUS表达（Yoshida和Takeda）。(2)含细胞分裂素的培养基和高温条件对克服烟草杂种致死性是有效的。在稻属中，高温条件也是有效的（丸桥）。(3)利用RT-PCR进行差异筛选的结果表明，分离体细胞和合子胚胎发生过程中优先表达的基因的潜力很大（吉田）。(4)作为一种新的农艺策略，建议将表达嵌合基因的双丙氨膦抗性水稻植株接种纹枯病病原体的菌丝体，随后用除草剂处理，完全保护其免受症状感染（内宫）。

1) The main objective of the Indian group was to develop methods for genetic improvement of Brassica juncea. (1) Through embryo rescue culture, over 20 intergeneric hybrids between wild species and different cultivars have been produced. Attempts were also made to achieve in vitro fertilization to overcome pre-fertilization barriers, but without success. Cytoplasmic male sterile lines of B.juncea with the cytoplasmic background of Diplotaxis siifolia has been reached an advanced stage (Shivanna). (2) In B.juncea, the Production of androgenic embryo were extremely poor and another problem of the pollen embryos was the inability to germinate normally. As the results on attempts to improve conditions of the donar plant and methods of tissue culture, the pollen embryo have become to germinate with high efficiency. Moreover, preliminary attempts were made to transform the pollen embryos. The construct pBI 121 loaded on gold particles were bombarded into the pollen embryos, in the University of Tokyo (Bhojwani).2) The Japanese group have studied to develop the new techniques different from the Indian group. (1) When the method of polyornithine was applied to in vitro pollination in Tabacco, transient GUS expression in pollen tubes was confirmed (Yoshida and Takeda). (2) The medium containing cytokinin and high temperature conditions were effective for overcoming hybrid lethality in Nicotiana. In Oryza, high temperature conditions were also effective (marubashi). (3) The results on differential screening using RT-PCR indicated a high potential to isolate genes that preferentially express during somatic and zygotic embyogenesis (Yoshida). (4) It was suggested as a new technique for agronomic strategies that Bialaphos resistant rice plants expressing a chimeric gene which were inoculated withmycelia of the sheath blight disease pathogen and subsequently treated with the herbicide were completely protected from symptomatic infection (Uchimiya).