Indian Society of Genetics & Plant Breeding


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KEEPING in view the low chromosome number (2n= 16), essentially cross-pollinated
nature, high forage yields of good quality, the spread of the harvest over several
cuttings and the diploid status of
Trifolium alexandrinum L. (Egyptian clover, berseem),
and encouraged by the success of the induced autopolyploids in red clover, Trifolium
and alsike clover, Trifolium hybridum (Levan, 1948) chromosome doubling was
induced in this important and popular forage crop of the irrigated tracts of northern
India at the Indian Agricultural Research Institute in 1954 (Mehta and Swaminathan;
1957; Sikka, Mehta and Swaminathan, 1959). The tetraploid cultures, in addition to
possessing the usual characteristic features associated with autopolyploidy, such as
increase in the size of cells, stomata, pollen and seed and reduction in pollen and seed
fertility, showed superiority in growth, vigour and tillering and thus held out considerable promise for the improvement of
berseem through "polyploidy breeding" (Sikka,
Swaminathan and Metha, 1958). Detailed studies on growth, cytological behaviour
and seed fertility of C" C
2 and C3 cultures have been made by Mehta, Subramanyam
and Swaminathan (1963) and the breeding potentialities and economic characteristics
of the tetraploid cultures have been investigated by Chaudhary, Appa Rao and Mehta
(1964). In the present study, some distinctive-looking tetraploid cultures were
critically evaluated during the
rabi 1959-60 under broadcast sowings, with the diploid
as control, in respect of forage yield, stem/leaf ratio, dry matter content, yield of seed
per plant and per unit area and regeneration after each cutting. A summary of these
observations is presented in this paper.


Year: 1964
Volume: 24
Issue: 2
Article DOI: NA
Print ISSN: 0019-5200
Online ISSN: 0975-6906



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