Japonia Rice Beeding Using Anther Culture

Abstract

Anther culture was used in Japonica rice breeding two seasons a year in the past five years. The modified N6 medium was used for callus fromation and a differ-entiation medium for plant regeneration. About 67,000-159,000 anthers from F1's of 25-36 rice crosses were inoculated to produce about 1,500-15,000 green plants per season for selection. Percentages of anther callusing ranged mostly from 21% to 31% and at most 66.6%. The number of crosses was later reduced to 2-3 to produce more than 13,000 green plants per season. The seed harvested from them were progeny-tested, and the strains established from the selected progenies were entered in yield trials. Although desirable recombinants were recovered in the progenies as expected, they generally appeared to be weak and lack of vigorous plant growth. In yield tests involving strains derived from anther culture and pedigree method, only 1-2 among 6 top-yielding strains were from anther culture. So far, 2 strains have reached the final selection and got into regional tests. It took only 3 seasons to complete a breeding cycle by the anther culture, saving 1/4-1/2 and 2/5 in average the time needed. 以改良N6培養基誘導癒合組織之形成而分化培養基引發植株之分化，將花藥培養應用於梗稻育種，每年二期作，繼續五年。每期作從25~36雜交組合第一代雜種取約67,000至159,000個花藥，培養得約1,500~15,000綠色植株。癒合組織之形成變異於21%至31%之間，最高有66.6%。每期作所用之組合數後來減少至2~3，並培養13,000以上之綠色植株。由此等植株所得種子用於後裔檢驗及篩選。當選的後裔成立為品系，列入於產量比較試驗。如所預料，重組的基因型出現於後裔，但這些品系多數顯示軟弱缺乏旺盛的生長力。花藥培養品系與譜系法育成品系一起參加產量試驗，6個最高產品系中只有1~2品系來自花藥培養。至目前為止有2品系通過產量比較試驗，進入區域試驗。應用花藥培養只需三期作即可完成育種一個循環。節省時間約1/4至1/2，平均約2/5。