ÃÞ»¨Ñ§±¨ Cotton Science 2005£¬17(3)£º155-159
Plant Growth and Development and Yield Performance of Various Bt Cotton Genotypes Abstract£ºFive non-hybrid and 2 hybrid Bt cotton cultivars developed in Shandong province, as well as their control cultivar 33B, were grown for four consecutive years (2001—2004) in Linqing or Ji'nan. Plant growth parameters, yield and yield components of each genotype were examined each year. Results showed that 5 non-hybrid Bt cottons might be divided into two groups according to their maturity performances. The first type (SCRC18 and SCRC22) with a growing period of 122 d from planting to boll opening, appeared similar to 33B in plant growth and development and the earliness of maturity£¬but its lint yield was increased by 5%-6% as a result of enhanced dry biomass per plant, boll weight or Lint percentage relative to that of 33B. The second group (SCRC16, SCRC17, SCRC21) , with significantly enhanced plant growth and development before flowering, and increased boll weight and lint percentage, exhibited enhanced earliness of maturity and 5%-7% higher yield than 33B. Total number of bolls per plant and the biomass ratio of root to canopy differed significantly between the two groups of Bt cotton. Optimal combination of yield components was observed in two hybrid Bt cottons (SCRC15 and SCRC20) , which were increased by 18%-19% in average lint yield compared to 33B. It is concluded that yield potential of indigenously developed Bt cottons, particularly the hybrid Bt cottons, is greater than that of the introduced Bt cotton like 33B. Moreover, the fact that Bt cottons with the same Bt gene differed in plant growth and development as well as yield components, probably suggests no absolute correlation between plant growth and the Bt gene.
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