RA 00110.pdf - OAR@ICRISAT

Androgenesis and Enzymatic Diversity in Pearl Millet
Androgenesis in Pearl Millet
(Androgenese chez le mil)
N. Mallikarjuna and J.K. Bhalla
Cytogenetics Laboratory, Department of Botany, Osmania University, Hyderabad, Andhra Pradesh 500 007,
India
Rice, barley, rye, wheat, maize, potato, and tobacco are often cited as examples in which haploids have not
only been produced but are being routinely used in crop improvement programs. However, the production of
haploids in semi-arid tropical crops such as pearl millet, sorghum, groundnut, chickpea, and pigeonpea, has
had little investigation.
For pearl millet, there are only two reports on the production of haploids (Ha and Pernes 1982, Nitsch et al.
1983). Both produced plantlets from microspores, but there was no indication of efficiency of the breeding
method.
Panicles with uninucleate microspores of three pearl millet cultivars were cultured on four different
standard basal media: MS, N6, B5, and Nitsch with 3% sucrose, 0.66% agar, and 1 ppm 2,4-D. The responses
of the cultivars differed, but WC-C75 was the most responsive.
Of the four different basal media, MS medium was the best for this cultivar. It induced androgenesis in more
than 50% of the anthers cultured. After 10 d of culture, divisions in microspores were observed. An average of
36 embryogenic microspores per anther were observed after 16 d of culture. The maximum number of
embryoids observed in one anther was 134. Acetocarmine squashes of the embryoids showed that they were
haploid with seven chromosomes.
Investigations on the subsequent development of the embryoids are in progress.
General Survey of Enzymatic Diversity in Pearl Millet
(Etude generate de la diversite enzymatique chez le mil)
S. Tostain and L. Marchais
ORSTOM c/o ICRISAT Sahelian Center, B.P. 12404, Niamey, Niger
Exactly 130 accessions of pearl millet from West Africa, East Africa, India, and eight samples of wild millet (P.
violaceum) from Mali and Niger were analyzed by electrophoresis, for eight enzymes: alcohol dehydrogenase
( A D H ) , catalase (CAT), B-esterase (EST), glutamate oxaloacetate transaminase (GOT), malate dehydrogenase
( M D H ) , phosphogluconate dehydrogenase (PGD), phosphoglucoisomerase (PGI), and phosphoglucomutase
(PGM).
These enzymes are coded by 12 genes and 46 alleles. Measurements of genetic diversity, using principal
component analysis and discriminant function analysis, have shown that the eight wild accessions form a
distinct group. Among the cultivated accessions, four separate groups, presented in order of decreasing genetic
diversity have been identified: early millets from western and central Africa (from Senegal to Sudan), late
millets from the same area, Indian millets, and southeastern African millets. Within the early group, a
west-east cline has been observed for the allozymes P G M A1, PGI A3, A D H A4, and EST A4. A second set of
allozymes separates the early and late groups: C A T A l , A D H A7, EST A3, EST A6, and EST A7. Millets
from central Africa (Sudan and Chad) form a bridge between Indian and southeastern African groups. From
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