Sutkhet Nakasathien

New microsatellite markers isolated from mungbean (Vigna radiata (L.) Wilczek)

In this study, we reported the isolation and analysis of new polymorphic microsatellites in mungbean (Vigna radiata (L.) Wilczek). Twelve out of 210 primer pairs screened in 30 mungbean accessions gave polymorphism. The polymorphic markers detected two to three alleles per locus with an average of 2.08. Observed heterozygosity varied from 0 to 0.133, while expected heterozygosity ranged from 0.095 to 0.498. Tests for Hardy–Weinberg equilibrium (HWE) and pairwise linkage disequilibrium of the polymorphic loci revealed that all loci except MB‐SSR14 significantly departed from HWE and four pairwise combinations, viz. MB‐SSR14 vs. MB‐SSR42, MB‐SSR42 vs. MB‐SSR87, MB‐SSR114 vs. MB‐SSR121, and MB‐SSR175 vs. MB‐SSR231 significantly deviated from linkage disequilibrium. The markers are being used to study genetic diversity and genome mapping of mungbean.

Influence of nitrogen application on dry biomass allocation and translocation in two maize varieties under short pre-anthesis and prolonged bracketing flowering periods of drought

ABSTRACT Plants have evolved different mechanisms to survive under stress conditions. This field study was conducted to evaluate the influence of nitrogen (N) application on dry biomass allocation and translocation in two maize varieties under short pre-anthesis and prolonged bracketing flowering period of drought. Two maize varieties, ‘Pioneer 30B80ʹ and ‘Suwan 4452ʹ receiving N at 0 (control), 160 (optimal) and 320 (supra-optimal) kg ha−1 were subjected to short pre-anthesis and prolonged bracketing flowering periods of drought. Prolonged bracketing flowering period of drought had more suppressive effect on anthesis-silking interval, dry matter allocation and translocation, leaf greenness, contribution of current assimilates to grain (CCAG), kernel number, kernel weight and kernel yield of two maize varieties than a short pre-anthesis drought. Nitrogen application at optimal level was the best for all traits, except CCAG. The maize variety ‘Pioneer 30B80ʹ performed better under both drought types due to more root xylem vessels of large size and more accumulation of dry matter in leaves and roots than the variety ‘Suwan 4452ʹ. Therefore, the variety ‘Pioneer 30B80ʹ may be planted in drought prone environments and may be used in breeding program aimed at developing drought-tolerant cultivars.

Isolation and characterization of purple acid phosphatase gene during seedling development in mungbean

Purple acid phosphatases (PAPs), which are normally found in plant tissues, can hydrolyze a broad spectrum of phosphate esters. In this study, a mungbean [Vigna radiata (L.) Wilczek cv. KPS1] acid phosphatase gene (VrPAP1) was isolated from seedling cotyledons. The full-length of VrPAP1 cDNA contained an open reading frame of 1 644 bp encoding 547 amino acid residues with a predicted molecular mass of 62.07 kDa. Sequence analysis showed that VrPAP1 is purple acid phosphatase. RNA blot analyses indicated that the VrPAP1 accumulated during the first hour in cotyledons of germinating seeds and reached a maximum expression after 24 h and then decreased. The VrPAP1 mRNA was observed in cotyledons, hypocotyls and leaves but not in radicles or dry seeds. DNA blot analysis indicated that VrPAP1 is a single copy gene in the mungbean genome.