Interspecific Chromosome Homologies in Coix lacryma-jobi L. and C. gigantea Koen. (Maydeae).

Chromosomal basis of evolution in the genus Coix L. (Maydeae): a critical appraisal

“…The factors of instability harboured in the genomes of C. aquatica and C. gigantea destabilized that of C. lacrymajobi in the hybrid background, the significance of which is not known [25,[32][33][34].…”

“…Even when 4n forms are involved in hybrids, the number and type of multivalents also yield similar further information in these, and those in which the parental genomes cannot be distinguished as in hybrids of 2n and 4n C. lacrymajobi with 2n and 4n C. gigantea [4,32,35]. These studies facilitate an understanding of the origin of genomes, their relationships, mode and further course of evolution in the genus.…”

“…The occurrence of up to five heteromorphic (intergenomic) bivalents in both hybrids, involving C. aquatica, and some intragenomic pairing in C. lacrymajobi and C. gigantea, led to the conclusion that the haploid genome of 10 chromosomes in both the latter species comprises two subgenomes of five chromosomes each and that one of them is closely allied to C. aquatica genome and also has some homologies with the second subgenome [21,25,[32][33][34][35].…”

“…From the analysis obtained from the data of Rao [25] and Rao and Nirmala [32][33][34] it was found that the intergenomic pairing per cell between C. aquatica and C. lacrymajobi was 2.449, between C. aquatica and C. gigantea was 3.106 and between C. lacrymajobi and C. gigantea was 9.183.…”

“…The occasional occurrence of spontaneous vigorous F 1 hybrids between the two species, the rampant manner in which 3n reciprocal hybrids were produced spontaneously between 4n C. lacrymajobi and 2n C. gigantea [25,32] and between 2n C. lacrymajobi and 4n C. gigantea [4,15] whenever opportunities were available, indicate that hybridization between them occurs frequently enough, and further the survival and spread of 3n sterile hybrid populations through vegetative reproduction in China, all provide presumptive evidence in support of the present hypothesis of the allopolyploid origin of C. gasteenii. However, it should be pointed out here that Simon [57] mentions that some of the Queensland herbarium specimens of cultivated or naturalized taxa in Queensland under the name C. lacrymajobi have male raceme dimensions of C. gigantea and for this reason they are more appropriately placed under C. gigantea.…”