Capsicum species are very important in Brazil because of economic, cultural and biological factors, and the country is considered to be a diversity center for this genus. Collection and maintenance of the genetic diversity in Capsicum are important to avoid genetic erosion. Besides the identification of species, the characterization and evaluation of accessions maintained in gene banks are of fundamental importance. For this purpose, multivariate methods have become an important tool in the classification of conserved genotypes. The objectives of this study were: i) to identify and characterize accessions of the Capsicum spp collection and draw conclusions about the potential use of certain accessions in different production sectors; ii) to estimate the genetic divergence among accessions using the Ward-MLM procedure, and iii) to evaluate the efficiency of the analysis of continuous and categorical data using the Ward-MLM procedure. Fifty-six Capsicum spp accessions were evaluated based on 25 descriptors, 14 of which were morphological and 11 agronomic. Based on the qualitative descriptors, it was possible to identify all species and, together with the agronomic descriptors, genotypes could be indicated with potential for use in various production sectors. Five was determined as the ideal number of groups by the criteria pseudo-F and pseudo-t 2 . The Ward-MLM procedure allowed the differentiation of the species C. annuum, C. frutescens, C. baccatum, and C. chinense in separate groups. The Ward-MLM procedure showed some level of efficiency in clustering Capsicum species analyzing morphological and agronomic data simultaneously.

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-Reciprocal recurrent selection among full-sib families is one of the outstanding methodologies of maize improvement, since gains are possible in the per se and/or in cross populations. Here the selection index proposed by Smith and Hazel was used in the cited methodology; besides, an additional phase involving RAPD markers was introduced to preserve the genetic variability of the selected genotypes and identify contaminants before their recombination. Multivariate techniques of grouping and discriminant analyses were used for this purpose, to assure the continuance of the improvement program and amplify the genetic distance between the populations Cimmyt and Piranão, which were used for an intervarietal hybrid. The molecular technique proved useful to identify contaminants and helpful in the choice of the genotypes to be recombined to maximize heterosis among populations. The technique can be included in recurrent selection programs, mainly those that target the development of hybrids.

ABSTRACT. Considering the expected genetic variability of elephant grass (Pennisetum purpureum), due to its cultivation in different continents, we characterized and estimated the genetic divergences between 46 accessions of elephant grass with different edaphoclimatic adaptations, using RAPD and ISSR markers. We evaluated, comparatively, the consistency of the information achieved with these markers. Twenty-six RAPD and 25 ISSR primers were employed. The RAPD markers produced 185 bands, 72% of which were polymorphic, with a mean of 5.11 polymorphic bands per primer. The 25 ISSR starters produced 216 bands; 76% were polymorphic, with a mean of 6.56 polymorphic bands per primer. The correlation between the genetic distances achieved by the RAPD and ISSR markers was 0.76, which is highly significant by the Mantel test. Based on UPGMA grouping, considering the point of sudden change, five and six groups were formed for the data from the RAPD and ISSR markers, respectively. Genetic diversity in elephant grass These markers provided partially concordant groups, indicating that these techniques can provide consistent information and consequently could be used in studies of genetic diversity among accessions.

Soil water limitations can cause high losses in agricultural yields. In order to investigate how popcorn varieties are affected by reduced water availability, we evaluated grain yield (GY) and popping expansion (PE) of 20 popcorn lines under water stress (WS) and well-watered conditions (WW), to propose discrimination with regard to the level of water-stress tolerance (T) and agronomic water-use efficiency (WUE), as well as to identify crosses for the breeding of superior hybrid combinations and for inheritance studies. A randomized complete block design with three replications was used. Irrigation was applied at pre-anthesis. The germplasm was discriminated based on the Stress tolerance index (STI), Stress susceptibility index (SSI), Stability index (SIN), Drought resistance index (DRI), and Agronomic water-use efficiency (WUE). Genetic diversity was measured by 15 EST-SSR markers. The reduction in GY under water stress was 55.29% and PE was reduced 29.19%. For the identification of genotypes with higher phenotypic means, STI and WUE were similarly efficient, whereas SSI and SIN identified genotypes with a lower proportional performance loss in the WS compared to the WW environment. For both GY and PE, there was a lack of relationship between WUE (more productive) and T (more ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 17 (4): gmr18184 S.H. Kamphorst et al. 2 stable). To explore the allelic complementarity for WUE, for T and for both, respectively, the combinations L59 x P7, L55 x P1 and L71 x P6 had the best performances. The lines L61, L63 and L65 phenotypically contrasted to those with high WUE and T and could be used for inheritance studies. Genotypes with higher WUE are considered the most appropriate option for breeding programs under WS.