Evaluation of different spring rapeseed (Brassica napus L.) genotypes for shattering tolerance

Abstract

In order to study tolerance to shattering, 5 spring rapeseed genotypes including Option 500, Sarigol, RGS003,
Hyola 401 and Hyola 60 were evaluated in a split plot experiment with 4 replications during two years. The
main plots were included 4 harvesting dates including H1: harvesting at seed color changing of ninety
percentage of pods in main stem (physiological maturity), H2: harvesting 10 days after the first harvesting of
each genotype, H3: harvesting 20 days after the first harvesting of each genotype and H4: harvesting 30 days
after the first harvesting of each genotype. Sub plots were included 5 studied genotypes. The differences of
seed yield of each genotype in different harvesting dates with compare to its seed yield in first harvesting date
(H1-Hi) were considered as indices of shattering. Combined analysis of variance based on split-plot
experiment revealed significant mean squares for genotypes, harvesting dates and harvesting × genotypes
interaction effects and also year and its interaction effects to each studied factors. In this study, Hyola 401
and Sarigol had 3994 and 3267 kg.ha-1, respectively. Significant mean square of genotype × harvesting dates
revealed different ranks of shattering of genotypes in different harvesting dates. Amount of seed yield
shattering was increased in third and fourth harvesting dates. On the basis of shattering index, Hyola-60 and
Hyola 401 were more tolerant to shattering and Sarigol as well as Option 500 were more susceptible to
shattering.