Nelumbo - The Bulletin of the Botanical Survey of India

A. H. Khan ¹, G. R. Rao ¹, Reayat Khan ¹

Affiliations
1 Aligarh Muslim University, Aligarh, IN

Abstract

Cytomorphological characteristics of Indian hexaploid S. nigrum and S. nodiflorum and of their F₁hybrids were studied. The parents differed significantly in several morphological and cytological characters. The hybrids were highly sterile and did not set seed.

They showed a wide range of meiotic irregularities. In several pollen mother cells, trivalents and quadrivalents were recorded, although in a very low frequency, in addition to a large number of univalents and bivalents. Occasionally bridges with or without fragments, were recorded. The results of these investigations show that chromosomal differences as well as genic differences have played an important role in reproductive isolation and morphological differentiation of the two species.

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Reayat Khan ¹, G. R. Rao ¹, A. H. Khan ¹

Affiliations
1 Department of Botany, Aligarh Muslim University, Aligarh, IN

Abstract

Biosystematic studies have been carried out on some species of the Solanum nigrum complex, viz., diploid S. nigrum, S. nadiflorum, tetraploid S. nigrum, S. luteum and S. villosum. A comparison of fruit colour and chromosome number of the taxa divides them into two groups. Diploid S. nigrum and S. nodiflorum have shiny bluish black fruits and n = 12 chromosomes. In tetraploid S. nigrum the fruits are orange red while in S. luteum and S. villosum the fruits are yellow and the chromosome number in all the three taxa is n = 24. Meiosis was normal in all the species. The close relationship between diploid S. nigrum and S. nodiflorum, and among the species tetraploid S. nigrum, S. luteumand villosum has been confirmed by cytogenetical studies and statistical comparison of mean values of morphological characters.

In the light of the foregoing studies a taxonomic revision of the species studied is suggested.

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