Characterization of three Okra [Ablemoschus (L.)] accessions using morphology and SDS-PAGE for the basis of conservation

Abstract

Okra [Abelmoschus (L.)] is native to Africa where it is an essential vegetable. It can be eaten raw, partially or well-cooked with wide range of edible parts. The taxonomy of the genus is regarded as complex. Hence, this study aims to characterize three Okra accession based on agro-morphological and biochemical characteristics. The Okra accessions were collected from National Center for Genetic Resources and Genetics (NACGRAB), Ibadan. Twenty five agro morphological characters were assessed including vegetative, quantitative and fruit characters such as main stem, stem colour, branching, stem base diameter, stem pubescence, leaf shape, leaf length, leaf width, petiole lenght, fruit colour, fruit shape and nature of fruit tip. SDS-PAGE was used to characterize soluble protein extracted from the Okra accessions. Result from the number of days to 50 % germination show that all the accessions recorded over 50 % germination from the fourth day. An assessment of stem and leaf vegetative character show that the stem colour ranged from green to red and red to purple, petiole and adaxial and abaxial surface of the lamina showed similar coloration. High level of variability was observed in the quantitative characters of the traits. The result of fruit character showed similarities between accessions NGAE-96-0011B and NGAE-96-0064C. It could not be obtained for accession NHGB-09-008A because it was yet to fruit during the period of study. Their biochemistry was also investigated using SDS-PAGE technique (using soluble protein profiling), the results showed that the proteins used as markers were effective in characterization of Okra in systematic studies. Visible and highly reproducible bands were produced. The indications of bands in the protein profiling showed more similarities among the esculentus species and distinguished them from the caillei species in the band compositions. The study suggest that two of the accessions are esculentus (NGAE-96-0064C and NGAE-96-0011B) while NHGB-09-008A is caillei. Therefore, it can be suggested that the variability observed in this study for all traits assessed were indicative of the differences in the genetic make-up of the cultivars considered.