Associations Between Bracts and Several Agronomic Traits in Cotton1
- D. T. Bowman and
- J. E. Jones2
Cotton (Gossypium hirsutum L.) bracts, as part of the trash in machine-harvested seed cotton, have been implicated in the brown lung disease, byssinosis, in mill workers. As part of two separate investigations into the genetic nature of bract surface area (cm2 of bract area), genotypic and phenotypic correlations were calculated to determine linkages or associations with several agronomic traits. These field studies were conducted at Alexandria and Baton Rouge, La. on typic udifluvents and aquic fragiudaif soils, respectively. Significant positive associations in both studies between bract surface area and boll weight suggested little progress would be made in reducing the bract relative to the boll if only the bract surface area was considered. A better measure of heritable changes in bract surface area relative to boll weight may be the ratio of bract surface area/lint weight per boll. A low ratio of bract surface area/lint weight per boll would denote a low bract trash potential and may denote a low byssinosis potential. The ratio bract surface area/lint weight per boll appeared to be positively associated (genotypically) with 50% span length, and negatively associated with fiber micronaire and lint percent. These associations would suggest that parents with high lint percent and parents with small bracts should be selected. The potential problem with fiber length and micronaire should be considered in breeding cottons for low bract trash potential.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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