Chromosomal Interchanges Evidence for Duplication

Chromosome Aberrations in Two Haploid Derivatives of <i>Sorghum</i>

“…Such an evidence for the existence of duplicate segments in the haploid genome is in conformity with previous report (Endrizzi andMorgan 1955, Schertz 1963). In one of the haploid derivatives of the present study, the extra chromosome undergoes synapsis in one of its arms with a pair of homologues in the normal complement, to give rise to a chain of three.…”

“…Although such plants have been recovered among the haploid progenies of Sorghum (Endrizzi andMorgan 1955, Schertz 1963) meiotic behaviour in the two haploid derivatives of the present study showed marked differences. Therefore, results obtained through analysis of chromosome pairing in these two plants are reported in this communication.…”

Chromosome Pairing in Haploid <i>Sorghum</i>

“…That the exchange of chromatin material follows chiasmatic bivalent formation is evident from the recovery of plants carrying translocations, among the progenies of haploids (Endrizzi andMorgan 1955, Schertz 1963). In the present study of two haploid Sorghum plants a maximum of 2 chiasmatic bivalents were encountered in a proportion of the cells at diakinesis and metaphase I.…”

Female Fertility of Haploid Peppers

“…Monosomics, trisomics, and reciprocal translocations due to crossing-over between homologous regions of otherwise dissimilar chromosomes have been reported in the Fl progeny of haploids (Kihara and Nishiyama 1937, Sears 1939, Endrizzi and Morgan 1955, Reddi 1971). An average of one seed per hand-pollinated fruit was obtained from haploids of C. annuum.…”

“…If this occurs with appreciable frequency, the difficulties inherent in treatment with colchicine would be circumvented. If seeds are formed as a result of failure of the first or second division, useful variants in chromosome number and structure would be anticipated due to atypical meiosis in haploids (Kihara and Nishiyama 1937, Sears 1939, Endrizzi and Morgan 1955, Reddi 1971. Line G168A, derived by colchicine treatment of a haploid of the variety Goliath, produces haploids with a higher than average frequency (Campos and Morgan 1960 number of 12 chromosomes.…”