Parental selection strategy for improving fibre strength and maintaining lint yield in cotton

• Published in: Industrial crops and products 2019-03, Vol.129, p.585-593
• Main Authors: Koebernick, Jenny C., Liu, Shiming, Constable, Greg A., Stiller, Warwick N.
• Format: Article
• Language: English
• Subjects: Combining ability; Correlation; Cotton; Fibre strength; Heritability; Lint yield
• ISSN: 0926-6690; 1872-633X
• DOI: 10.1016/j.indcrop.2018.12.040

•High fibre strength needs to be combined with high yield to sustain grower profitability.•Additive gene effects primarily contributed to fibre strength.•Lint yield was moderately but negatively correlated with fibre strength.•Crossing high strength with high yield cottons locally adapted improves both fibre strength and yield. There is a consistent demand to improve cotton fibre quality from both the producer and the end user. However, this is a major hurdle for breeders due to its negative association with yield. This study investigated the breeding values of different cotton fibre strength sources for improvement without compromising lint yield. A North Carolina mating design II was performed between five high yield locally bred female parents (>2100 kg/ha) and four high fibre strength male parents (>31 g/tex) to obtain 20 crosses. Their F1’s were grown in the glasshouse and the F2’s and F3’s in the field, for two years, to determine general and specific combining ability of lint yield and fibre quality traits. The general combining ability effect was much larger than specific combining ability effect in determining significant variability among the crosses, implying that all traits were controlled primarily by additive gene action. Heritability estimates were moderate to high (0.36 ∼0.80) for lint percentage and fibre quality traits except fibre maturity. Lint yield had a moderate negative association with fibre strength. Early generation tests in the glasshouse and field identified the same good combiners. Acala Ultima and Sicala 40 were good general combiners for high fibre strength but poor for lint yield. However, two new locally bred high strength parents had positive general combining ability for both yield and fibre strength. Therefore, adapted high strength parents must be chosen first in crossing to achieve improvements in not only strength but also other quality traits and yield, demonstrating the importance of adaptation in parent selection in breeding for both yield and quality.