Heterosis and Line-Tester Analysis in Gossypium Barbadense L. Cotton. II. Fibre Quality

Eight intra-Gossypium barbadense hybrids producing 80–100% higher yield than the best fibre quality cv. Savin were identified. The fibre quality characters like mean fibre length (MFL), 2.5% span length (SL), uniformity ratio (UR), micronaire value (MIC), per cent mature fibres (MP), fibre tensile strength at 0 (0-STR) and 3 mm guage (3-STR) and fibre elongation (E₁) of the hybrids, cv. Suvin and Chy. DCH-32 were assessed. Four hybrids possess nearly equal SL (36.4–37.0 mm) to that of cv. Suvin {37.3 mm). The same four hybrids depicted superior fibre characters to Suvin in UR (46–47), MIC (3.2–3.4), MF (83–91), 0-STR (10.21–10.36), 3-STR (32.20–35.06), and E₁ (10.6–12.1). Heterosis over respective midparent values of hybrids was nonsignificant, indicating additive gene control of SL, UR, MIC and 0-STR, in majority of hybrids but MFL, 3-STR and E₁ were determined by nonadditive gene action. It is suggested to exploit hybrid vigour shown by crosses of BCS 9–70 with TCS 30-6, TCS 3–5 aad TCS 9–5 cotton strains for increasing productivity of superior quality barbadease cotton in India.