Genetics of breeding characters with possible effects on biomass production in Salix viminalis (L.)

Genetic variation in number of sylleptic shoots, wood density, dry matter content, flower production, budbreak, growth cessation, insect susceptibility and rust susceptibility and the relationships of these characters with other growth characters were studied. Forty of sixty-four families in an 8 X 8 factorial crossing with Salix viminalis were used. Fourteen plants from each family were planted in the framework of a nutrient experiment with optimal and suboptimal nutrient availability and in a sandy soil. The analyses showed high additive genetic variances for all characters studied. Characters measured in both nutrient environments did not show any genotype X environment interaction. Both in the nutrient and in the sand environment insect susceptibility was negatively correlated to different growth characters. This was also the case for rust susceptibility in the sand environment. The highest negative correlation was found between number of days to budburst and weight, indicating the importance of early budburst for production. Ideas on important characteristics for an Salix ideotype are discussed.