Abstract: Numerical analysis on the cotton boll structure in thirty breeding parents of gland-less cotton cultivated in period of the Seventh Five-Year Plan in China was carried out when the bolls in the whole plants opened completely. The results of star site cluster and grey system analysis indicated that the cotton boll composition yield value of five groups of breeding parents decreased clockwise and progressively in the star site cluster chart. Excellent common and inferior class of parents generally belonged to mid ripening and early-mid ripening glanded cotton,mid ripening and early-mid ripening glandless cotton and early ripening cotton varieties respectively. The dry matter in boll of excellent class of parent was centralized by lint,and that of inferior one-by kernel. The results of multi-level path coefficient analysis indicated that the relationship between characters of cotton bolls belonging to different parents was different,and it had consistent relation to the characters of parent groups.

Key words: Glandless cotton, Cotton boll structure, Star site, Grey system evalua-tion, Coherence coefficient, Multi-level path analysis