Recurrent selection (RS) is a method of selection by crossing selected plants from systematic population to develop new superior population. The recurrent selection had been implemented in local varieties to produce drought tolerance and blast resistance of rice lines. This research was conducted at

Mutants of Spathoglottis plicataBlume were obtained from plants treated with Gamma Irradiation at 30-100 Gray. The mutants showed variations in the flower morphology. The objective of this experiment was to identify genetic variations of orchids S. plicataand its mutants using inter-simple sequent repeat (ISSR) markers. The amplified product of 10 ISSR primers produced 360 bands and 71 ISSR of the loci (90.14%) were polymorphic. The coefficient of similarity and principal component analysis produced five major groups with similarity coefficient of 0.68. The goodness of fit correlation matrix value reached 0.91. Therefore the ISSR isa good marker for identification of S. plicatamutants.Keywords: gamma irradiation, ISSR marker, mutant, orchid

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Organic material is widely used for propagation of orchids, namely coconut water, extracts of tomatoes, bananas, bean sprouts and potatoes which can be added to certain media as a provider of nutrients, amino acid minerals, and growth regulators. This study aims to determine the effect of the concentration of organic matter in coconut water and banana extract on MS media on the regeneration of PLB (protocorn like bodies) Dendrobiumgatton sunray. The study was conducted at the Biotechnology Laboratory, Faculty of Agriculture, Bengkulu University, from September to December 2019. This study used a Complete Randomized Block Design (RCBD) with two factors. The first factor was the concentration of coconut water with 3 levels namely: A0 = 0 (Control), A1 = 75 ml.L -1 , A2 = 150 ml.L -1 , and the second factor was the concentration of banana extract with 5 levels namely: B0 = 0 (Control), B1 = 75 g.L -1 , B2 = 150 g.L -1 . The results showed that coconut water did not affect all variables, however the banana extract had a significant effect on all variables except for the number of shoots. There was an interaction between the two treatments, namely the variable plantlet weight. Orthogonal polynomial analysis showed that there was an interaction between the two treatments, where coconut water and banana extract had a good response on the plantlet growth when given together as much as 75 ml.L -1 (A1) and 75 g.L -1 (B1). The concentration of both treatment was lower than it was given individually.

Multi-environment yield trials are essential in an estimation of genotype by environment (GE) interaction and identification of superior genotypes in the final selection cycles. The objective of this study was to evaluate yield stability of five hybrid maize in three locations using AMMI (Additive Main Effects and Multiplicative Interaction) method. A randomized block design with three replications was applied to the experiment at each site. The genotypes tested were UNIB CT5, UNIB CT8, UNIB CT9, UNIB CT13, and UNIB CT14. The hybrids were single-crosses from selected pairs of S6 gamma irradiated mutant parental lines. The hybrids were cultivated in three different locations with different agroclimatic. They were Air Duku village, district of Curup, Rejang Lebong (rainy season of the year of 2014); Kandang Limun village, district of Muara Bangkahulu, Bengkulu (wet season of the year of 2015) and Medan Baru village, district of Muara Bangkahulu, Bengkulu (dry season of the year of 2015). The results showed that among five newly developed hybrids tested, CT8 and CT9 were the most prospective genotype for Ultisol for a dry and wet season, respectively. Based on the postdictive success and predictive success methods, the model used (AMMI 2) was able to explain 89% interaction-influenced variation. The genotypes found stable in three locations based on AMMI analyses was UNIB CT14. Three hybrids were considered specific adaptation. They were UNIB CT9 for rainy season of Kandang Limun, UNIB CT8 for dry season of Medan Baru and UNIB CT13 for rainy season of Curup. UNIB CT5 did not adapt to any of the three environments tested.