Rice with polyembryony characterized bytwin seedlings is a good genetic tool for apomixisresearch.A study on the effect of five plantgrowth regulators(IAA,KT,GA,2,4-D and6-BAP)on rate of twin seedlings in 3 rice varie...Rice with polyembryony characterized bytwin seedlings is a good genetic tool for apomixisresearch.A study on the effect of five plantgrowth regulators(IAA,KT,GA,2,4-D and6-BAP)on rate of twin seedlings in 3 rice varie.ties with polyembryony(Shuang 3,Shuang 13and Lu 52)was conducted.The results showed展开更多
A high-efficiency somatic embryogenesis protocol of Japanese larch （Larix leptolepis Gordon） has been established in our investigation. Calli were induced from immature zygotic embryos of female cones ofL. leptolepi...A high-efficiency somatic embryogenesis protocol of Japanese larch （Larix leptolepis Gordon） has been established in our investigation. Calli were induced from immature zygotic embryos of female cones ofL. leptolepis and then subcultured regularly on to a modified Gupta and Durzan （DCR） basal medium for 5 years. Embryogenic tissues showed distinct morphological changes dur- ing somatic embryo development when they were transferred to a maturation medium supplemented with abscisic acid （ABA） com- pared with the morphology in a medium lacking ABA. Histological observations indicated that polyembryony was a characteristic feature during early embryogeny and somatic embryos at later stages showed normal histodifferentiation. In addition, histochemical analysis revealed that abundant starch granules and proteins accumulated in mature embryos, indicating that they played important roles in the development and regeneration of normal plantlets from somatic embryos on hormone-free germination media展开更多
Polyembryony is a serious handicap in citrus breeding. To obtain zygotic off-springs, monoem-bryonic seed parents were usually used in breeding programs. Kiyomi, a superior monoembryonic tangor, was used as seed paren...Polyembryony is a serious handicap in citrus breeding. To obtain zygotic off-springs, monoem-bryonic seed parents were usually used in breeding programs. Kiyomi, a superior monoembryonic tangor, was used as seed parent in 7 cross combinations. When pollen parents was Chandler pummelo or Tarocco blood orange, only monoembryonic seeds were observed. However, when Washington Sanguine, Li-xing orange and Bing-tang orange were used as pollen parents, no more than 7. 2% of polyembryonic seeds were observed. Interestingly, while male parents were Nucellar3 Ponkan and Oota Ponkan, high ratio of polyembryonic seeds was observed. The ratio of polyembryonic seeds was steadily at about 30 % in two consecutive years and was obviously different from other results reported. Polyembronic seeds were observed in monoembryonic varieties sometimes, but normally their ratios were no more than 7%. Polyembryonic-seedlings were got by separating the multi-embryos in seeds of Kiyomi×Nucellar3 Ponkan and then their leaves were used in RAPD analysis. Identical bands of male parent and/or different bands from seed parent were found in most of the polyembryonic-seedlings and so it can be sure that these seedlings were of zygotic origin. Some pairs of polyembryonic-seedlings have identical bands in all tested primers and may be resulted from zygotic embryo divisions. Different bands were found in other pairs of polyembryonic-seedlings also and this may indicate multi-egg fertilization or other source of variation.展开更多
文摘Rice with polyembryony characterized bytwin seedlings is a good genetic tool for apomixisresearch.A study on the effect of five plantgrowth regulators(IAA,KT,GA,2,4-D and6-BAP)on rate of twin seedlings in 3 rice varie.ties with polyembryony(Shuang 3,Shuang 13and Lu 52)was conducted.The results showed
基金the National Natural Science Foundation of China （Grant No. 30471366） the National Science Fund of China for Distinguished Young Scholars （30225005）.
文摘A high-efficiency somatic embryogenesis protocol of Japanese larch （Larix leptolepis Gordon） has been established in our investigation. Calli were induced from immature zygotic embryos of female cones ofL. leptolepis and then subcultured regularly on to a modified Gupta and Durzan （DCR） basal medium for 5 years. Embryogenic tissues showed distinct morphological changes dur- ing somatic embryo development when they were transferred to a maturation medium supplemented with abscisic acid （ABA） com- pared with the morphology in a medium lacking ABA. Histological observations indicated that polyembryony was a characteristic feature during early embryogeny and somatic embryos at later stages showed normal histodifferentiation. In addition, histochemical analysis revealed that abundant starch granules and proteins accumulated in mature embryos, indicating that they played important roles in the development and regeneration of normal plantlets from somatic embryos on hormone-free germination media
文摘Polyembryony is a serious handicap in citrus breeding. To obtain zygotic off-springs, monoem-bryonic seed parents were usually used in breeding programs. Kiyomi, a superior monoembryonic tangor, was used as seed parent in 7 cross combinations. When pollen parents was Chandler pummelo or Tarocco blood orange, only monoembryonic seeds were observed. However, when Washington Sanguine, Li-xing orange and Bing-tang orange were used as pollen parents, no more than 7. 2% of polyembryonic seeds were observed. Interestingly, while male parents were Nucellar3 Ponkan and Oota Ponkan, high ratio of polyembryonic seeds was observed. The ratio of polyembryonic seeds was steadily at about 30 % in two consecutive years and was obviously different from other results reported. Polyembronic seeds were observed in monoembryonic varieties sometimes, but normally their ratios were no more than 7%. Polyembryonic-seedlings were got by separating the multi-embryos in seeds of Kiyomi×Nucellar3 Ponkan and then their leaves were used in RAPD analysis. Identical bands of male parent and/or different bands from seed parent were found in most of the polyembryonic-seedlings and so it can be sure that these seedlings were of zygotic origin. Some pairs of polyembryonic-seedlings have identical bands in all tested primers and may be resulted from zygotic embryo divisions. Different bands were found in other pairs of polyembryonic-seedlings also and this may indicate multi-egg fertilization or other source of variation.
