Embryogenic calli were obtained from a hybrid line of Sorghum bicolor (L.) Moench anthers with mid to late uninucleate pollen cultured in N6 medium supplemented with 3.0% sucrose, 2.0 mg/1 2,4-D, 0.8% agar and incubated at 30°C, which was the optimum temperature. The regeneration of embryos was obtained from the embryogenic calli cultured in modified MS medium supplemented with 3.0% sucrose, 2.0 mg/1 BAP combined with 0.3 mg/1 IAA and 0.8% agar. A total of 248 doubled haploids and 12 haploid plants were regenerated. In a subsequent field study, the selfed progeny from anther culture (designated as the anther culture-2, [A2] generation) derived families was compared with both the F2 and the F1 for agronomic and morphological traits. Significant differences were noticed between the family means of both A2 and F2 for all the quantitative traits studied. The distinctive difference in the behavior of the A2 families in comparison with the F2 was established by within family variance, which was significant in F2 for days to 50 per cent flowering, plant height, panicle length, leaf area index, dry matter production, harvest index and grain yield and was non-significant in A2. Male sterility, one of the potentially important traits, currently exploited in the hybrid seed production of cereals, including CSH5 hybrid sorghum and the morphological traits (panicle shape, compactness, grain color, glume color and nature of the leaf sheath) segregated in the F2. Such segregation was not observed within A2 families and they bred true to their respective A1 plants, indicating the rapid attainment of homozygosity/uniformity. The present study establishes the gametophytic origin of anther culture derived families and indicates the possibility of rapid production of homozygous lines which can be used as recombinant inbreds.

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The cytology of thirteen taxa and two hybrids in the genus Pennisetum indicated the distribution of the taxa among the four basic chromosome numbers 5, 7, 8 and 9. The diploid nature of P. ramosum and P. typhoides and the genomic allotetraploid status of P. purpureum was further confirmed. P. massaicum (2n = 32), P. orientale (2n = 36) and P. subangustum (2n = 36) suggested probable autotetraploid nature and the three hexaploids (2n = 54) investigated (P. polystachyon, P. longistytis and P. squamulatum) revealed allohexaploid constitution. The natural triploid, P. ruppellii (2n = 27) and pentaploid P. villosum (2n --45) were found to be apomiets and they were allotriploid and allopentaploid respectively. The tetraploid-hexaploid complex of P. pedicellatum showed them to be cytotypes only. The cytogenetical behaviour of the hybrid, P. typhoides × P. purpureum with 2n = 21 and the trispecies hybrid (P. typhoides × P. purpureum) x P. squamulatum with 2n = 48 brought out the homology within the genomes of x = 7 and x = 9 and also between the genomes with x = 7 and x = 9. The significance of the inter-and intragenomic chromosome pairing had been brought out from the interspecific hybrids and the natural allotriploid and allopentaploid species having one genome in the haploid condition.The morphological sections of this genus did not correspond with the cytological groups. A high degree of evolutionary specialization was evident in species of the section Gymnothrix. A complete series of polyploids and a high degree of heterogeneity from the morphological point of view was brought out in species with x = 9.

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