Induction of Triploid Plants from Local Citrus Cultivars in Vietnam
Pummelos (Citrus grandis) and Cam Sanh (King mandarin; Citrus nobilis) , are two most important citrus species in Vietnam. Currently, two naturally derived and excellent quality seedless pummelo cultivars (Nam Roi and Da Xanh) are in wide production for local consumption and export. The study showed the seedlessness of these varieties is because of gamete-incompatibility. The seedlessness is not stable and highly varied depending on availability of outcrossing, which is negatively influencing on trademark of pummelo export. The advantage of Cam Sanh is high quality, well adapted to different ecological and climatic conditions, but seedy. For improving pumelo and King mandarin, the research for breeding of seedless triploids has been conducted. Tetraploids, Phuc Trach pumelo (4n) and Cam Sanh (4n), were obtained by in vivo colchicine treatment of axillary buds of mature shoots of Phuc Trach and Cam Sanh. The method allowed to rapidly received flowering tetraploid plants (2 years after colchicine treatment) and greatly shortened time (4-6 years) for inducing triploids in comparison with colchicine treatment of somatic embryogenic callus, multiple shoots in vitro or treatment of seeds where the regenerated tetraploid plants are of long juvenility time (6-8 years). The pollens of Phuc Trach (4n) have been pollinated to different famous pummelo cultivars of country to produce triploids. The production of fruit with viable seeds is varied between crosses. Average number of seeds with viable embryos from crosses Buoi Dien (2n) X Phuc Trach (4n) and Doan Hung (2n) X Phuc Trach (4n) is 7. 0 and 6. 0 seeds per fruit, respectively. From cross between two ploidy levels of the same cultivar: Phuc Trach (2n) X Phuc Trach (4n), the average number of viable seeds is only 2.0 seeds per fruit. Method of embryorescue in vitro has been applied for regenerating plants from mature and immature seeds of hybrid combinations. Ploidy levels of regenerated plants have been identified by flow cytometry. Numerous triploid plants have been obtained. Among 282 plants regenerated from seeds of cross Buoi Dien (2n)×Phuc Trach (4n) , 264 plants were triploids (93.62％), 6 were tetraploids (2.13％ ), the remaining 12 plants are diploids (4.25％ ). The method of embryorescue is also applied for regenerating triploid plants from small and aborted seeds of diploid cultivar Cam Sanh. Among 679 regenerated plants, 38 plants were triploids (5.59％ ). All the triploids have been grafted on the adult citrus plants for study the possibility of shortening juvenization period for triploid breeding and field test.
Citrus cultivars Mutation breeding Triploid Vietnam
Do Nang Vinh Ha Thi Thuy Tran Ngoc Thanh Tran Thi Hanh Nguyen Thi Chien
Institute of Agricultural Genetics, Hanoi, Vietnam
国际会议
11th International Citrus Congress(第11届国际柑橘大会)
武汉
英文
265-271
2008-10-01（万方平台首次上网日期，不代表论文的发表时间）