-A backcross breeding program between commercial common bean cultivars (VC3 and M20)

-This study aimed to determine the minimum number of plants per plot to assess the field resistance in common bean to white mold. Thirteen cultivars were inoculated with six isolates of Sclerotinia sclerotiorum and evaluated in a randomized block design with three replications and plots consisting of 1-m rows with 15 plants. Plants were inoculated by the straw test as proposed by Petzoldt and Dickson (1996)

Performance of soybean crosses in successive generations of inbreeding, with emphasis on yield, tolerance to rust and earliness Among the main demands of Brazilian agriculture in recent years highlights the need for soybean cultivars with high yield potential, resistance / tolerance to diseases, mainly Asian soybean rust (FAS) and reduced cycle. The research aimed to study the genetic relationships of soybean crosses in different generations of inbreeding and selection, with an emphasis on the seed yield, resistance/tolerance to rust and cycle (earliness). The 49 crosses was obtained in a partial diallel 7x7, researching the generations F 2 and F 2: 3 by Oliveira (2011) and, in this work, the generations F 2:4 , F 2:5 , F 5:6 and F 5:7. A total of ten experiments (combinations of agricultural years, locations and disease managements) were performed in augmented block and or randomized complete-block designs. The two managements involved one experiment with control of the late season leaf diseases (DFC) and rust, whereas the second experiment only involved the control of the DFC. The following traits were evaluated : seed yield (PG), one hundred seed weight (PCS, representing the seed size), number of days to maturity (NDM), plant height at maturity (APM), lodging (AC), agronomic value (VA), notes of rust severity (NF) and the rust reaction rates (TRF). The TRFs for each trait were estimated by the difference between the adjusted means of each genotype in the two experiments with diseases managements. There were obtained analyses of variance and estimates of heritability, average combining ability (CMC), the CMC correlations between generations, correlations between traits, selection of superior experimental lines and the selection gains. The methodologies for measuring the rust resistance by severity notes (NF) and the rust tolerance (TRF) allowed the discrimination of genotypes and showed evidences of being complementary and with benefits for use together. Higher evidences of CMC correlations between generations were observed in the high heritability traits. The magnitude of the variability within crosses oscillated due the selection and the progeny/line opening, for most of the traits. Even with negative correlations between traits (NDM x PG and NDM x NF), there were observed gains in the selection of superior genotypes. The parents who contributed most to obtain experimental lines with high seed yield, rust resistance / tolerance and earliness were M-Soy 8001 and IAC 100 in the Group I, and USP 70.080 and USP 70.123 in the Group II of the diallel.

Diseases can cause negative impacts during all stages of development of soybean [Glycine max (L.) Merr.] Asian soybean rust (ASR) (caused by Phakopsora pachyrhizi) is the most destructive. The impact of ASR on vegetable soybean (consumed when the seeds are still immature) have not been studied rigorously. Thus, in a 2-yr study, we assessed 42 F 6 lines from crosses of soybean vegetable genotypes and three commercial cultivars ('BRS 257', 'BRS 267' and 'IAC 100') in two sites. During the R 6 and R 8 development stages, the genotypes were evaluated for 10 traits.The joint analysis showed that the interactions were significative for the most traits. The significance of the rust effect allowed us to identify the genotypes in which the losses were nonsignificant. We observed that ASR affected two stages of plant development. However, information about ASR losses quantified by the rust reaction rate (RRR) enabled the researchers to select lines that could be used in breeding programs aiming towards ASR tolerance. We found three lines that were superior to one of the cultivar checks. Furthermore, cluster analysis for RRR was useful in establishing the most promising groups of vegetable soybean genotypes for use in hybridization aiming to expand the genetic base for vegetable soybeans and integrate new genetic resources of vegetable soybean in the Brazilian genetic pool to ensure genetic gain.