SUMANA NGAMPONGSAI1, VEERANA SINSAWAT FORRER1, ARADA MASARI1, ACHARA JOMSA-NGAWONG1, FONGSEN YANG1, THEWA MAOLANONT1, DUMRONG JIRASUTAS2, SOMCHAI CHANNARONGKUL3
1Chai Nat Field Crops Research Centre, Department of Agriculture, Thailand
2Office of the Deputy Director General, Department of Agriculture, Thailand
3Office of the Director General, Department of Agriculture, Thailand
The Vigna genus has 7 subgenus spread around the tropics and subtropics of Asia, Africa and America. Of those, only subgenus Ceratotropis is originated in Asia thus commonly known as Asian Vigna. The Thai Department of Agriculture has continuously conducted a survey and collection of wild Vigna genetic resources in Thailand as well as introduced from overseas. Lately, 66 samples of wild Vigna genetic resources under threats were collected countrywide for a safe keep. In 2009, a total of 102 accessions (accs.) of wild Vigna from 22 species were grown in order to regenerate, evaluate and safely duplicate at Chai Nat Field Crops Research Centre, Thailand. The most found species were V. umbellata (18 accs.), V. minima (13 accs.), V. reflexo-pilosa (11 accs.), V. radiata (11 accs.), V. trinervia (10 accs.), V. mungo (10 accs.). These were from a local collection together with accessions introduced from overseas. Being a viny and indeterminate type, they were grown in pots with sticks to support the stems. Each accession was characterised and evaluated for morphological characteristics and agronomic traits using the IPGRI descriptor for mungbean (V. radiata). The results showed that, given the differences in their own genetic, location, soil type, microclimate and imposed threats, the morphological characteristics and agronomic traits of wild Vigna varied dramatically. For example, terminal leaflet shapes varied from cuneate (42 accs.) to ovate"=lanceolate (28 accs.), ovate, or deltoid. Petal colour, the typical characteristic of the subgenus Ceratotropis, varied from light to dark yellow. The number of days to harvest varied between 49 to 122 days (average 7518 days). For agronomic traits, the number of pod per plant was from 12 to 688 pods (average 190140 pods). The number of seed per pod varied between 5-14 seeds (average 9 seeds/pod). Seed size varied between 5-82 g (average 2617 g/1000 seeds). Seed yield ranged between 1-68g/plant (average 2619g/plant). The morphological characteristics and agronomic traits were then recorded in a database for a sustainable use in efficient breeding programmes. Some of these wild Vigna genetic resources were also deposited in the Thai genebank for a safety duplication.
Keywords: Agronomic traits, Ceratotropis, evaluate, genetic resources, morphological characteristics, regenerate, safety duplicate, wild Vigna