MARKER ASSISTED SELECTION (MAS) FOR DEVELOPMENT OF BARLEY AND WHEAT LINES WITH REQUESTED TRAITS

Molecular markers closely linked to interesting genes enable early, proper and fast detection of plant individuals with desired allele during backcross breeding, what can make plant breeding faster and cheaper. We are focused on molecular breeding of barley and wheat lines for disease resistance and some important quality traits. As acceptors of interesting genes we use especially elite Slovak and Czech cultivars and lines. After five backcross generations with the help of MAS new created lines carrying markers linked to desired genes undergo resistance, agronomic and technological tests. In breeding of winter barley for resistance to BaYMV/BaMMV viruses we use codominant STS and SSR markers linked to rym4 and rym11 resistance genes. Cultivar Romanze has been used as a donor of rym4 gene and landrace Russia57 as gene rym11 donor. In spring barley we are focused on transfer of Yd2 gene from landraces Shannon and Sutter resistant to BYDV by use of dominant ASPCR marker. We are also working on transfer of effective leaf rust resistance genes Lr19, Lr24 derived from Thinopyrum ponticum and gene Lr35 from Aegilops speltoides into hexaploid wheat by use of dominant STS and SCAR markers. Near isogenic lines with these genes are used in gene pyramiding to develop a single line with all three genes. By use of protein markers we develop near isogenic wheat lines for higher sedimentation values, higher dough strength and better breadmaking quality. These are lines with new combination of HMW glutenin subunits (21*, 7+8, 5+10) as well as wheat lines with new unknown HMW-GS and with new HMW-GS pair

Genetic diversity among Brazilian soybean cultivars based on SSR loci and pedigree data

In this study, simple sequence repeats (SSR) loci and pedigree data were used to investigate the genetic relationship in a group of 168 Brazilian soybean cultivars. Eighteen SSR loci produced an average of 5.06 alleles and a mean gene diversity of 0.58 for the cultivars studied. Genetic distance (GD) was determined using the modified Roger's Wright distance, and a final dendrogram was in agreement with the cultivar pedigree. A distance matrix based on the coefficient of parentage scores was also generated for the cultivars, which ranged from 0 to 1, with a mean of 0.18, whereas SSR-based genetic similarity (1- GD) ranged from 0.01 to 0.90, with a mean of 0.25. Mantel's Z test showed that the similarity matrices generated from both the data sets were low, but significantly correlated (r = 0.31, p<0.001). The results showed that SSR data and pedigree analyses could help to quantify more accurately the degree of relationship among the soybean cultivars.<br>Locos microssatélites e dados de genealogia foram utilizados para avaliar a diversidade genética de um grupo de 168 cultivares brasileiras de soja. Os dezoito locos utilizados apresentaram em média 5,06 alelos por loco e coeficiente de diversidade genética médio de 0,58. O dendrograma final resultante da matriz de distância genética de Roger modificado por Wright, apresentou boa concordância com a ancestralidade dos grupos formados. Também foi estimado os coeficientes de parentesco entre as cultivares, sendo observada variação de 0 a 1 com média de 0,18, enquanto que as similaridades para os locos microssatélites (1- GD) variou de 0,01 a 0,90 com média de 0,25. A correlação entre as duas matrizes obtidas determinada pelo teste Z de Mantel apresentou valor baixo, 0,31, mas significativo (p<0,001). Os resultados obtidos sugerem que os locos microssatélites aliados às informações de genealogia proporcionam melhor análise da diversidade genética de cultivares de soja