Plant pre-breeding for increased protein content in soybean Glycine max (L.) Merrill

Abstract

The aim of this research were to determine protein content and genetic divergence of soybean genotypes in QTL regions of the trait grain protein content for plant breeding purposes. Twenty-nine soybean genotypes were grown in the field in four environments (Viçosa-MG Dec/2009, Visconde do Rio Branco-MG Feb/2010, São Gotardo-MG Feb/2010, and São Gotardo-MG Oct/2011) using the randomized block design with three replicates. The grain protein content was quantified by the infrared spectrometry method. The genetic divergence was estimated by the analysis of 39 microsatellite markers from QTL regions for the soybean grain protein content. The pairs of genotypes with greater genetic distances and protein contents were as follows: BARC-8/CS3032PTA276-3-4 (D=0.71) (45.18%/44.31%); BARC-8/CS3032PTA276-1-2 (D=0.71) (45.18%/43.75%); BARC-8/CS3032PTA190-5-1 (D=0.71) (45.18%/43.63%); B3PTA382-2-10/CS3032PTA276-3-4 (D=0.62) (43.80%/44.31%); CS3032PTA276-1-2/B3PTA382-2-10 (D=0.62) (43.75%/43.80%); B3PTA382-2-10/CS3032PTA190-5-1 (D=0.62) (43.80%/43.63%); B3PTA216-1-9/CS3032PTA276-3-4 (D=0.61) (43.48%/44.31%); and B3PTA216-1-9/CS3032PTA276-1-2 (D=0.61) (43.48%/43.75%), respectively. Other promising combinations for the improvement of protein content were as follows: BR8014887/CS3032PTA190-5-1 (D=0.57) (44.71%/43.63%); BARC-8/CS3032PTA182 (D=0.78) (45.18%/41.84%); BR8014887/CS3032PTA182 (D=0.65) (44.71%/41.84%); BR8014887/PI417360 (D=0.76) (44.71%/41.01%), respectively; and PI417360/B3PTA216-1-9 (D=0.80) (41.01%/43.48%). These pairs of genotypes when crossed should produce populations with higher means and genetic variances and greater gains with selection.Los objetivos de este estudio fueron analizar el contenido de proteína y la diversidad genética de genotipos de soya en regiones de QTL del contenido de proteína para fines de mejoramiento genético. Veintinueve genotipos fueron cultivados en el campo en cuatro ambientes (Viçosa-MG Dec/2009, Visconde do Rio Branco-MG Feb/2010, São Gotardo-MG Feb/2010, y São Gotardo-MG Oct/2011), utilizando un diseño de bloques al azar con tres repeticiones. El contenido de proteína se determinó por espectrometría del infrarrojos. La diversidad genética fue estimada por el análisis de 39 marcadores microsatélites de regiones de QTL del contenido de proteína en el grano. Los pares de genotipos con mayores distancias genéticas y niveles proteicos fueron BARC-8/CS3032PTA276-3-4 (D=0,71) (45,18%/44,31%); BARC-8/CS3032PTA276-1-2 (D=0,71) (45,18%/43,75%); BARC-8/CS3032PTA190-5-1 (D=0,71) (45,18%/43,63%); B3PTA382-2-10/CS3032PTA276-3-4 (D=0,62) (43,80%/44,31%); CS3032PTA276-1-2/B3PTA382-2-10 (D=0,62) (43,75%/43,80%); B3PTA382-2-10/CS3032PTA190-5-1 (D=0,62) (43,80%/43,63%); B3PTA216-1-9/CS3032PTA276-3-4 (D=0,61) (43,48%/44,31%); y B3PTA216-1-9/CS3032PTA276-1-2 (D=0,61) (43,48%/43,75%). Otras combinaciones prometedores para mejorar el contenido de proteína son BR8014887/CS3032PTA190-5-1 (D=0,57) (44,71%/43,63%); BARC-8/CS3032PTA182 (D=0,78) (45,18%/41,84%); BR8014887/CS3032PTA182 (D=0,65) (44,71%/41,84%); BR8014887/PI417360 (D=0,76) (44,71%/41,01%); y PI417360/B3PTA216-1-9 (D=0,80) (41,01%/43,48%). Estos pares de genotipos cuando cruzados debe producir poblaciones con mayores medias y varianzas genéticas y mayores ganancias con la selección.