陸地棉과 亞細亞棉의 種間交配時 生長調節劑 處理가 着삭에 미치는 影響

Effect of growth regulators on boll bearing in interspecific pollination between Gossypium hirsutum L. and G. arboreum L.

The present cotton cultivars were bred mostly for spinning. Accordingly their fibers are not satisfactory in elasticity, strength and water absorption, which are very important properties when they are used as padding or sanitary purposes. Interspecific hybridization was carried out with a hope to incorporate the high yield potential and early maturity of upland cottons, Gossypium hirsutum, with the highly elastic and strong fibers and excellent water absorption of Asiatic cottons, G. arboreum. Various methods such as application of growth regulators to the pollinated flowers, pollination on cut stems, pasting the stigma with pollen germination media, in vitro culture of hybrid ovules and doubling the chromosomes of the F₁ hybrid plants were attempted to overcome the interspecific barriers. An aqueous solution of 100㎎/ℓ NAA and 50㎎/ℓ GA₃ applied to the interspecifically pollinated flowers and then substantially delayed the fruit drops as shown by 49.5% bolls retained in 20 days after pollination compared to 10.9% in the control. Number of seeds harvested per interspecific cross was 0.017 on G. hirsutum and 0.008 on G. arboreum, even through all of them were empty and failed to germinate.