IDENTIFICATION OF A RING OF FOUR AND TWO CHAINS OF THREE CHROMOSOMES FROM THEGOSSYPIUM ARBOREUM-HIRSUTUMRING OF SIX

Abstract

Cytological tests of a ring of four chromosomes and two chains of three chromosomes showed that they were derived from the Gossypium arboreum-hirsutum ring of six. In the identification of the chromosomes in the ring of four it was concluded that the ring of six contains a differential pairing segment and that the ring of four is a secondary structural change due to crossing-over in the differential segment The possibility that the differential segment includes a pair of centromeres is discussed. It was concluded that the two chains of three were the result of a specific type of 24 unequal disjunction of the ring of six.