Seed Coat Pattern QTL and Development in Cowpea (Vigna unguiculata [L.] Walp.)

The appearance of the seed is an important aspect of consumer preference for cowpea (Vigna unguiculata [L.] Walp.). Seed coat pattern in cowpea has been a subject of study for over a century. This study makes use of newly available resources, including mapping populations, a reference genome and additional genome assemblies, and a high-density single nucleotide polymorphism genotyping platform, to map various seed coat pattern traits to three loci, concurrent with the Color Factor (C), Watson (W), and Holstein (H) factors identified previously. Several gene models encoding proteins involved in regulating the later stages of the flavonoid biosynthesis pathway have been identified as candidate genes, including a basic helix-loop-helix gene (Vigun07g110700) for the C locus, a WD-repeat gene (Vigun09g139900) for the W locus and an E3 ubiquitin ligase gene (Vigun10g163900) for the H locus. A model of seed coat development, consisting of six distinct stages, is described to explain some of the observed pattern phenotypes.

CHARACTERIZATION OF SOME ALGERIANS AND FOREIGN LENTIL ACCESSIONS BY QUALITATIVE TRAITS

In the present study an attempt has been made to characterize lentil accessions based on qualitative traits. There were variations among 44 lentil accessions. Erect growth habit was observed in 24 % of the accessions where 8% were from Algeria. Conversely, prostrate growth habit was observed in 34% of the accessions. The majority of the remaining accessions (41.32%) were intermediate. Stem with anthocyanin pigmentation was showed in 44% of the accessions, whereas, 56% had no pigmentation (green stem). About half of the accessions had grey green leaves (53%) and 23% of accessions were light green. Among the characters, flower color showed the highest variation. White flowers were observed in 64% accessions and violet flowers were found in 36% accessions. Flowers, with violet stripes in the standard petal (SVE) were observed in 44% accessions and the majority (56%) lacked violet stripes. Yellow cotyledons were observed in 61% accessions, while the rest (39%) had red cotyledons. The majority of accessions (81%) were observed with brown testa while 14% were green and 5% had yellow testa. Absence of seed coat pattern was observed in 69% accessions. However, 8% accessions with spots, 5% with dots, 16% were marbled and the remaining 2% were complex. Flattened seed shape was observed in 60% of accessions. Conversely, globose shape was observed in 40% of the accessions, among of them 27% were from Algeria.

Morphological characterization of lentil accessions: Qualitative characters

Wide variability was observed for all the characters among 110 lentil accessions. Stem colour varied from normal green (45%) to purple (55%). Prominent and rudimentary tendrils were found in 60% and 40% of the accessions, respectively. Among the characters, flower colour showed the highest variation. White flower colour was observed in 49%, violet in 28%, white with blue veins in 20% accessions and the rest 3% were with blue flowers. Red cotyledon was shown by 90% while with yellow was shown by 10% of the accessions. Green, grey and brown seed coat was observed in 10, 66 and 24% of the accessions, respectively. Seed coat pattern with dots was found in 70% accessions and marbled seed coat pattern was shown by 15.5% while 14.5% did not show any seed coat pattern. DOI: http://dx.doi.org/10.3329/bjb.v41i2.13447 Bangladesh J. Bot. 41(2): 187-190, 2012 (December)