ABSTRACT: The aim of this study was to investigate the effect of heat stress on 12 bean genotypes through the analysis of their reproductive biology in terms of flowering, pollen viability, meiotic behavior, and production. Plants were grown in a climate chamber at 25-20 °C (day and night) and at a high temperature treatment 37-26 °C (day and night) from the vegetative (V4) development stage to physiological maturity. The experimental design was 2 × 12 factorial arrangement with six replications and the factors consisted of heat treatments and genotypes. In three replications, the number of newly opened flowers was checked daily. At physiological maturity, the following traits were evaluated: percentage of pod set, number of pods, number of viable seeds, number of aborted seeds, 100 seed weight, and seed yield (g per plant). The other three replications were used to collect flowers to create slides to study viability of the pollen grain and analyze the meiotic behavior. The heat treatment factor significantly affected the following traits: total number of pollen grains, number of flowers, number of pods, pod set, number of viable seeds, 100 seed weight, and seed yield. The raised temperature reduced these variables, except for percentage of pod set, and increased meiotic irregularities. The mean values regarding seed yield were 16.39 g per plant for the control treatment and 7.46 g per plant under high temperature. IAC Imperador, FT Nobre, Pérola, BRS Estilo, and IAC Diplomata stood out for higher bean seed yield under increased temperature.

ABSTRACT: Presence of the ALMT1 (aluminum-activated malate transporter) gene confers resistance to aluminum toxicity in Triticum aestivum (common wheat). No resistant cultivars of Triticum turgidum ssp. Durum Desf. (durum wheat) have been registered in Brazil. The aim of this study was to map the ALMT1 through application of the FISH (fluorescence in situ hybridization) technique in five wheat genotypes, common and durum, from the Active Germplasm Bank (AGB) of the Instituto Agronômico (IAC): BH 1146, P19, P33, Anahuac, and IAC 1003. FISH-ALMT1 signals were registered in Anahuac (sensitive) chromosomes and in BH 1146, P19, and P33 (resistant) chromosomes. In the three resistant genotypes, a characteristic double FISH signal was found, located in different chromosomes of the complements: in BH 1146 in chromosome 5D, in P19 in 3B, and in P33 in 6B. This FISH - ALMT1 mapping allows for introgression of aluminum resistance in sensitive cultivars through breeding programs using introgression lines containing these carrier chromosomes.

ABSTRACT Karyotyping and chromosome complement knowledge are a prerequisite for cytogenetic mapping. The aim of this study was to characterize 1 common wheat cultivar (BH 1146) and 4 durum wheat genotypes (IAC 1003, Langdon, P19 and P33) from the breeding program of the Agronomic Institute of Campinas (IAC), using karyotype analysis together with Chromomycin A3/4’-6-Diamidino-2-phenylindole (CMA/DAPI) banding techniques for longitudinal characterization of chromosomes and fluorescence in situ hybridization (FISH) in the mapping of the 45S rDNA region. Durum wheat chromosome complement number was 2n = 4x = 28 with the following karyotype formula: 22m + 6sm. Common wheat chromosome complement number was 2n = 6x = 42 with the following karyotype formula: 34m + 8sm. Tetraploid and hexaploid genomes presented 2 pairs of chromosomes with secondary constriction and terminal satellites. All 5 wheat genotypes exhibited CMA and DAPI bands and signals in the 45S rDNA regions (FISH-probe pTa71) which varied in number and location on the chromosome complement. All lines showed greater amount of DAPI bands than CMA bands. The FISH-rDNA 45S in situ hybridization signals, related to the nucleolar organizing regions (NORs), were observed in common wheat, presenting signals for the 45S rDNA sequence in 3 pairs of chromosomes. Durum wheat presented signals in 2 pairs. The CMA bands coincided with the location of 45S rDNA region in the chromosomes of durum wheat. The techniques were efficient for chromosomal characterization of all 5 genotypes.

Objetivou-se neste trabalho quantificar a diversidade genética entre genótipos de milho-pipoca comerciais e em fase de recomendação no Brasil em três ambientes, utilizando 11 características agronômicas e marcador molecular do tipo ISSR. O ambiente de Campos dos Goytacazes revelou a formação de grupos que foram mais consonantes quando comparados com os outros ambientes. Nos dados moleculares verificou-se a presença de cultivares recomendadas em mesmo grupo, como ocorreu com UFVM2 Barão de Viçosa, IAC 125, Zélia e Jade. Esse resultado é um motivo de alerta para os poucos melhoristas de milho pipoca do Brasil, no sentido de promoção de maior diversidade genética entre programas de melhoramento realizados por instituições públicas e privadas no país. Verificou-se uma correlação praticamente nula entre a matriz de distância obtida pelo marcador ISSR com as matrizes obtidas pelos dados agronômicos.

The purpose of this study was to quantify the genetic diversity among popcorn genotypes on the market and in the final test phase, suitable for three environments in Brazil, based on 11 agronomic traits and ISSR markers. In the environment Campos dos Goytacazes a more reliable group formation was observed than in the other environments. The molecular data indicated the presence of cultivars recommended in the same group, as in the case of UFVM2 Barão de Viçosa, IAC 125, Zélia and Jade. This result is an appeal to the few popcorn breeders in Brazil to pay particular attention to increase the genetic diversity among breeding programs conducted by public and private institutions in the country. There was virtually no correlation between the distance matrix obtained by the ISSR marker and the matrices obtained by the agronomic data.