Cytoplasmic effects of CMS-D2 in upland cotton

Abstract

<p indent="0mm">Two sets of isonuclear alloplasmic near-isogenic restorer lines of <italic>Gossypium harknessii</italic> were planted in cotton production areas of the Yellow River (Anyang, Henan) and Yangtze River (Jiujiang, Jiangxi) basins, and comparative analyses of seedling growth, leaf photosynthetic parameters, anther development, cotton yield as well as its constituent factors, and fiber quality traits were performed to clarify the cytoplasmic effects of CMS-D2 in upland cotton. The results are as follows: (i) sterile cytoplasm did not affect cotton seedling growth and most fiber quality traits. (ii) The net photosynthetic rate of the sterile cytoplasmic restorer lines was significantly higher at the seedling stage but lower after the blooming stage when compared to the fertile cytoplasmic restorer lines. (iii) The anther fertility of the sterile cytoplasmic restorer lines under high-temperature stress was significantly lower than that of the fertile cytoplasmic restorer lines, which was mainly manifested in a significant reduction in pollen amount, pollen activity and vitality. (iv) The sterile cytoplasm negatively affected yield traits, which was mainly manifested in a significant reduction in boll number per plant and lint percentage. (v) In general, the negative effects of sterile cytoplasm on net photosynthetic rate, anther development and cotton yield were more obvious in cotton production area of the Yangtze River basin where summer temperatures are higher. This paper systematically explored the effects of CMS-D2 cytoplasm on the main traits of upland cotton, and the results of this study are of great significance for the breeding and improvement of cytoplasmic sterile “three-line” hybrid cotton.