Precocious Flowering of Citrus Seedlings and Short Juvenility of Poncirus Seedlings: Usage for Genetic Analysis and Breeding
Precocious flowering of Citrus seedlings and short juvenility of Poncirus seedlings were investigated with many cultivars for rapid genetic analysis and for shortening of the long breeding terms. The experiment with one- to twelve-month-old nucellar seedlings of grapefruit showed that the seedlings germinating in August had the highest rate of precocious flowering because of their appropriate number of expanded leaves for flower initiation during winter and spring. The temperature required for flower bud initiation in these nucellar seedlings was best in greenhouse conditions (> 10℃), followed by 258℃/15℃(16hrs day/8hrs night; 70％ r. h. ). When these seedlings were decapitated above their basal node in August of the second year and when the newly developed shoots were grown under natural conditions, about 30％ of the new shoots produced flowers in next spring. The hybrid seedlings derived from crosses with grapefruit showed the highest rate of precocious flowering. Citrus cultivars that generated zygotic seedlings with the ability of precocious flowering were detected in pummelos, pummelo hybrids and mandarins, suggesting most Citrus cultivars are heterozygous for the genes controlling precocious flowering in seedlings. A monoembryonic and male sterile hybrid (HY16) derived from a Yuzu× Hanayu cross was useful for identification of polyembryonic cultivars heterozygous for precocious flowering genes, and for genetic analysis of male sterility. Some trifoliate orange (Poncirus trifoliata) cultivars generated hybrid seedlings with short juvenile period of one or two years. The segregation of zygotic seedlings with the short juvenile character in F1, S1, and BC1 generations suggested that the short juvenility was a genetic character and also useful for genetic analysis in trifoliate oranges.
Citrus Poncirus Precocious flowering Short juvenility
Jung-Hee Kim Akira Wakana Tsuyoshi Sekiya You Tanimoto Binh Xuan Ngo Kaori Sakai
Faculty of Agriculture, Kyushu University, Fukuoka 812-8561, Japan Thai Nguyen University of Agriculture and Forestry, Thai Nguyen, Vietnam
国际会议
11th International Citrus Congress(第11届国际柑橘大会)
武汉
英文
326-334
2008-10-01（万方平台首次上网日期，不代表论文的发表时间）