DEVELOPMENT OF DOUBLED HAPLOID RICE LINES AND THEIR CHARACTERIZATION
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Date
2019-02-08
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UNIVERSITY OF AGRICULTURAL SCIENCES, GKVK BENGALURU
Abstract
Doubled haploid technology has the greatest advantage of generating completely
homozygous lines from any segregating population and contributes in shortening the
breeding cycle of new varieties. With an aim of identifying the best DH lines which can
be popularized as varieties, the present study was taken up to develop DH lines using
anthers of KRH4 rice hybrid through androgenesis technique. Panicles with uninucleate
to early binucleate stages microspores were collected and pretreated with cold and
mannitol and cultured on basal N6 medium with Auxin and Cytokinin in 1:1 ratio in
which a good callusing was observed. Similarly, with regeneration media, good
regeneration was obtained. With polymorphic SSR markers, diploids were identified and
eliminated, while with flow cytometry analysis, true haploids and spontaneously formed
doubled haploids were identified. The true haploids (colchicine treated) and
spontaneously formed doubled haploids were hardened and raised them in greenhouse
conditions. The seeds from these plants were labeled as DH-0 generation seeds and
altogether, seeds were produced from 27 DH plants out of which 21 lines were initially
characterized during kharif 2016 and the remaining 6 lines during summer 2017 both
under aerobic condition and identified some promising DH lines. The promising DH lines
were characterized likewise both during summer and kharif 2017 both under puddled and
aerobic condition. When analyzed for stability, the traits were indeed shown to be stable.
Further, the truthfulness of the DH lines over generations was checked and found to be
true DH lines. Based on these, it can be inferred that the DH lines are stable across
seasons, locations and over generations. The DH lines were also found to have good
cooking quality as well. Finally, based on the yield potential, two DH lines namely, DH 4
and DH 19 were nominated for All India trial.