Genotype by environment assessment in sweetpotato as leafy vegetable using AMMI model

The genotype by environment (G×E) interactions can be observed by differential genotypic responses to varied environmental conditions. Its effect is to limit the accuracy of yield estimates and complicate the identification of specific genotypes for specific environments. The objective of this study was to use the Additive Main Effects and Multiplicative Interactions (AMMI) method, with additive effects for genotypes and environments and multiplicative terms for genotype by environment interaction for analyzing data of 6 sweetpotato genotypes at 8 agro-environments. Results indicated that genotypes MIB05 and MIB14 were suitable for vegetable use for their higher shoot yield despite the root yield was low but they had low stability among agro-environments especially for 2 environments in Pontian, Johor with peat soil but these genotypes are suitable for 2 seasons of Telong, Kelantan. More breeding efforts are needed in order to improve the yield stability of these genotypes. AMMI biplot analysis has shown its advantage as helpful tool in identifying the best genotype for improving leafy vegetable for a new cycle of crossing and selection. Moreover, results indicated that MIB20 (control variety) had high stability with low interaction effects in eight agro-environments

Genetic variability of sweet potato (Ipomoea batatas Lam.) genotypes selected for vegetable use

The presence of high variability among sweetpotato (Ipomoea batatas (L) Lam.) genotypes for morphological characters, especially shoot tips, used for vegetable is important to plan effective breeding programs. An experiment was carried using selected twenty-two genotypes from germplasm and farmers collections. The objective was to estimate the nature and magnitude of variability among morphology, yield and yield components and organoleptic traits in the sweetpotato. Observations were recorded on twenty-two characters. The analysis of variance revealed that there were highly significant (p<0.01) differences among the genotypes for all the characters. Wide ranges of genotypic variability were observed among the genotypes for most of the characters. In morphological traits, 11.5 to 100% of the observable variability was due to the genetic variation while in yield and yield components this value ranged from 91.67 to 100% indicating the existence of immense inherent variability among the genotypes. Meanwhile, in organoleptic traits the value ranged from 19.63 to 29.5% of the observable variability and was due to higher phenotypic variability than genotypic contribution suggesting that the role played by the testing panels in expressing their scores on palatability vary greatly. High genotypic coefficients of variation along with high heritability were recorded for petiole length and leaf area in 10 cm tip in morphological characters, whereas, in yield and yield components the traits were total shoot and root yield and in organoleptic traits it was tenderness. Thus, future improvement of the genotypes could exploit the genetic variability available in these germplasm collections

Callus Induction from Zygotic Embryos of Coconut MATAG F2

The effect of 2,4-D (in concentrations of 5.0, 10.0, 20.0 and 40.0 mg/L) applied in combination with BAP (1.0, 10.0 and 20.0 mg/L) on callus induction in coconut MATAG F2 zygotic embryos cultured on Murashige and Skoog (MS) medium was investigated. The effects of IBA, TDZ and NAA combined with 2,4-D were also tested. The best callus formation (20%) was obtained on MS medium supplemented with 2,4-D at 10.0 mg/L. The induced calli were yellowish in colour and structurally compact. Different portions of the zygotic embryo were also compared for callus induction when used as explants and cultured on MS medium supplemented 10.0 mg/L 2,4-D. The incidence of callus formation (up to 83%) was highest from the middle portion of the embryos