In Guinea, traditional rice varieties are the most widely cultivated in rural areas despite their low yield and high susceptibility to iron toxicity. Moreover, the introduction of new improved varieties tolerant to ir...In Guinea, traditional rice varieties are the most widely cultivated in rural areas despite their low yield and high susceptibility to iron toxicity. Moreover, the introduction of new improved varieties tolerant to iron toxicity poses a serious threat to the preservation of the genetic resources of these traditional varieties, whose genetic diversity remains poorly known. The present study therefore aims at a better valorisation of these local rice cultivars through the evaluation of their agromorphological diversity and the identification of genotypes potentially tolerant or resistant to iron toxicity. Thus, 90 accessions collected in the regions of Kindia and Macenta and six controls susceptible or resistant to iron toxicity (AZUCENA, BOUAKE 189, CK 73, IR64, NERICAL 19 and AURYLUX 6) were evaluated in three replicate alpha lattice designs in two sites (Sérédou and Kilissi) using 16 agromorphological traits. The results showed significant agromorphological variability of the traditional accessions at both sites for all qualitative and most quantitative traits studied. In addition, 30 local cultivars expressed similar or higher grain yields than the resistant or tolerant controls at both sites, of which 12 were found to be stable at both sites. Of the 12 cultivars identified, five were resistant and seven tolerant to iron toxicity. These 12 accessions could be used in the varietal improvement of lowland rice in Guinea Conakry.展开更多
In Burkina Faso, sweet grain sorghum [Sorghum bicolor (L.) Moench] is generally cultivated in association with several other types of sorghum. However, the lack of information on the genetic relationship between this ...In Burkina Faso, sweet grain sorghum [Sorghum bicolor (L.) Moench] is generally cultivated in association with several other types of sorghum. However, the lack of information on the genetic relationship between this sorghum and grain sorghum as well as sweet stalk sorghum hinders the efficient management of its genetic resources. Thus, 34 sorghum accessions consisting of 14-grain sorghum, 10-sweet stalk sorghum, and 10 sweet grain sorghum were evaluated using 15 nuclear microsatellites markers (SSRs) to determine their genetic relationship. Results revealed significant genetic diversity within each sorghum type and a significant index of genetic differentiation per pair of sorghum types (0.017) between sweet grain sorghum and sweet stalk sorghum. The minimum Nei distance was also high (0.12) between these two sorghum types. Sweet grain sorghum indeed showed the lowest values of theoretical heterozygosity (0.35), of observed heterozygosity (0.13). Structuring of the accessions of the three types of sorghum cultivated in two distinct groups, one of grain sorghum and sweet stalk sorghum and another consisting of accessions of grain sorghum and sweet grain sorghum was also obtained. The low differentiation observed would suggest greater genetic proximity between the three types of sorghum. The differences observed would be more of a physiological and biochemical nature. These results could contribute to better management of the genetic resources of sweet grain sorghum.展开更多
文摘In Guinea, traditional rice varieties are the most widely cultivated in rural areas despite their low yield and high susceptibility to iron toxicity. Moreover, the introduction of new improved varieties tolerant to iron toxicity poses a serious threat to the preservation of the genetic resources of these traditional varieties, whose genetic diversity remains poorly known. The present study therefore aims at a better valorisation of these local rice cultivars through the evaluation of their agromorphological diversity and the identification of genotypes potentially tolerant or resistant to iron toxicity. Thus, 90 accessions collected in the regions of Kindia and Macenta and six controls susceptible or resistant to iron toxicity (AZUCENA, BOUAKE 189, CK 73, IR64, NERICAL 19 and AURYLUX 6) were evaluated in three replicate alpha lattice designs in two sites (Sérédou and Kilissi) using 16 agromorphological traits. The results showed significant agromorphological variability of the traditional accessions at both sites for all qualitative and most quantitative traits studied. In addition, 30 local cultivars expressed similar or higher grain yields than the resistant or tolerant controls at both sites, of which 12 were found to be stable at both sites. Of the 12 cultivars identified, five were resistant and seven tolerant to iron toxicity. These 12 accessions could be used in the varietal improvement of lowland rice in Guinea Conakry.
文摘In Burkina Faso, sweet grain sorghum [Sorghum bicolor (L.) Moench] is generally cultivated in association with several other types of sorghum. However, the lack of information on the genetic relationship between this sorghum and grain sorghum as well as sweet stalk sorghum hinders the efficient management of its genetic resources. Thus, 34 sorghum accessions consisting of 14-grain sorghum, 10-sweet stalk sorghum, and 10 sweet grain sorghum were evaluated using 15 nuclear microsatellites markers (SSRs) to determine their genetic relationship. Results revealed significant genetic diversity within each sorghum type and a significant index of genetic differentiation per pair of sorghum types (0.017) between sweet grain sorghum and sweet stalk sorghum. The minimum Nei distance was also high (0.12) between these two sorghum types. Sweet grain sorghum indeed showed the lowest values of theoretical heterozygosity (0.35), of observed heterozygosity (0.13). Structuring of the accessions of the three types of sorghum cultivated in two distinct groups, one of grain sorghum and sweet stalk sorghum and another consisting of accessions of grain sorghum and sweet grain sorghum was also obtained. The low differentiation observed would suggest greater genetic proximity between the three types of sorghum. The differences observed would be more of a physiological and biochemical nature. These results could contribute to better management of the genetic resources of sweet grain sorghum.
