Increasing seed oil content is an important breeding goal for Brassica napus L. (B. napus). The identification of quantitative trait loci (QTL) for seed oil content and related traits is important for efficient selection of B. napus cultivars with high seed oil content. To get better knowledge on these traits, a molecular marker linkage map for B. napus was constructed with a recombinant inbred lines (RIL) population. The length of the map was 1,589 cM with 451 markers distributed over 25 linkage groups. QTL for seed oil content, seed hull content and seed coat color in three environments were detected by composite interval mapping (CIM) tests. Eleven QTL accounted for 5.19-13.57% of the variation for seed oil content. Twelve QTL associated with seed hull content were identified with contribution ranging from 5.80 to 22.71% and four QTL for seed coat color accounted for 5.23-15.99% of the variation. It is very interesting to found that co-localization between QTL for the three traits were found on N8. These results indicated the possibility to combine favorable alleles at different QTL to increase seed oil content, as well as to combine information about the relationship between seed oil content and other traits.

In this study, the correlations among these characters were investigated in 18 rapeseed (Brassica napus L.) accessions with different seed coat color. The results indicated that seed water uptake and flooding tolerance were significantly correlated with seed color and melanin pigment content of testa. The red or black-seeded accessions had higher melanin content in testa, showed slower water uptake and lower leakage and higher flooding tolerance. The majority of yellow-seeded rapeseed accessions which had low melanin pigments content in testa showed a rapid water uptake and higher leakage than the red or black-seeded, which led to imbibition damage and lower flooding tolerance. The results suggest that the yellow-seeded cultivars experienced poor field emergence and more serious pre-harvest sprouting in raining weather than the dark-seeded cultivars. Some yellow-seeded accessions showed a slow imbibition behavior and relative high flooding tolerance, indicated these accessions can be used as a genetic resource to improve the flooding tolerance and reduce imbibition damage for the yellow-seeded B. napus L.

The majority of goats in Tanzania belong to the Small East African (SEA) breed, which exhibits large phenotypic variation. This study aimed to determine the genetic structure of, and relationships among four populations (Sukuma, Gogo, Sonjo, and Pare) of the SEA breed that have not been studied adequately. A total of 120 individuals (24 from each population) were analysed at eight microsatellite loci. In addition, 24 goats of the South African Boer breed were used as reference. Observed heterozygosity (Ho) ranged from 0.583 ± 0.04 for Sukuma to 0.659 ± 0.030 for Gogo, while expected heterozygosity (He) ranged from 0.632 ± 0.16 for Sukuma to 0.716 ± 0.16 for Boer. Five loci deviated from Hardy-Weinberg equilibrium (HWE) across populations. The mean number of alleles ranged from 4.75 ± 1.58 for Pare to 6.88 ± 3.00 for Sukuma. The mean inbreeding coefficient (F IS ) ranged from 0.003 in Sonjo to 0.148 in Sukuma. The differentiation coefficient (F ST ) was highest (0.085) between Boer and Sukuma and lowest (0.008) between Gogo and Sonjo. The largest genetic distance (0.456) was found between Sukuma and Boer, while the smallest (0.031) was between Gogo and Sonjo populations. Pare, Gogo, and Sonjo populations, formed one cluster, while Sukuma and Boer populations formed two separate clusters. From the findings, it can be concluded that the SEA goats in this study showed high in population genetic variation, which implies that there is good scope for their further improvement through selection within populations. The Sukuma population, which has fairly high inbreeding, is moderately differentiated from Pare, Sonjo, and Gogo goat populations, which showed a high level of admixture. Conservation and improvement strategies of the goats should be designed with first priority being on Sukuma goats.