Many tree planting programmes have long been initiated to increase forest cover to mitigate the effects of global climate change.Successful planting requires careful planning at the project level,including using suita...Many tree planting programmes have long been initiated to increase forest cover to mitigate the effects of global climate change.Successful planting requires careful planning at the project level,including using suitable species with favourable traits.However,there is a paucity of improvement data for tropical tree species.An experimental common garden of Shorea leprosula was established to study traits related to growth performance which are key factors in planting success.Seedlings of S.leprosula were collected from nine geographical forest reserves.To study the effects of genetic variation,seedlings were planted in a common environment following a randomized complete block design.From performance data collected 2017‒2019,one population showed the highest coefficient for relative height growth,significantly higher than most of the other populations.Interestingly,this population from Beserah also exhibited the lowest coefficient for scale insect infestation.This study provides preliminary results on growth performance and susceptibility to scale insect infestation in S.leprosula and the first common garden experiment site conducted on dipterocarp species.It lays a foundation for future genome-wide studies.展开更多
We studied seed germination and seedling growth performance in an economically and socially important fruit tree species <em>Vitellaria paradoxa</em> C.F. Gaertn. subsp. <em>nilotica</em> (shea...We studied seed germination and seedling growth performance in an economically and socially important fruit tree species <em>Vitellaria paradoxa</em> C.F. Gaertn. subsp. <em>nilotica</em> (shea tree) in Uganda. The study aimed at determining variations in germination among five shea tree seed provenances and seedling growth performance based on five growth traits (total height, root collar diameter, leaf length, leaf width and leaf petiole length). Five populations were considered from four agroecological zones comprising of 180 candidate “plus” trees. The seed trees consisted of 16 ethnovarieties selected based on their traits for fast growth and high oil yield. A total of 1,204 biological seeds were collected and sown in a tree nursery at Ngetta Zonal Agricultural Research and Development Institute during the month of June 2018 in a randomized incomplete block design with three replications. Significant variation (χ = 708;p < 0.01) was observed in seedling phenotypic traits within and between populations. Regression equation for height growth and leaf size index were given as y = 0.3787 + 12.671x and y = 0.6483 + 15.413x respectively. Root collar diameter was more correlated to leaf size index (0.425) than to height growth (0.30). Clustering of shea tree seedlings based on phenotypic growth traits revealed one aggregated cluster indicating that most of the seedlings from the five populations were similar (Jaccard index 0.92, p < 0.01). However, clustering based on SNP markers revealed three different populations. We recorded higher growth (χ = 708;p < 0.001) in Arua shea population. Red seeded;thin pulped and hairy fruited shea tree ethnovarieties recorded faster growth than the rest. The results reveal useful traits in selection for tree growth and further identified shea tree ethnovarieties that could be selected for fast growth.展开更多
基金supported by the Government of Malaysia under the 10th and 11th Malaysia Plan.
文摘Many tree planting programmes have long been initiated to increase forest cover to mitigate the effects of global climate change.Successful planting requires careful planning at the project level,including using suitable species with favourable traits.However,there is a paucity of improvement data for tropical tree species.An experimental common garden of Shorea leprosula was established to study traits related to growth performance which are key factors in planting success.Seedlings of S.leprosula were collected from nine geographical forest reserves.To study the effects of genetic variation,seedlings were planted in a common environment following a randomized complete block design.From performance data collected 2017‒2019,one population showed the highest coefficient for relative height growth,significantly higher than most of the other populations.Interestingly,this population from Beserah also exhibited the lowest coefficient for scale insect infestation.This study provides preliminary results on growth performance and susceptibility to scale insect infestation in S.leprosula and the first common garden experiment site conducted on dipterocarp species.It lays a foundation for future genome-wide studies.
文摘We studied seed germination and seedling growth performance in an economically and socially important fruit tree species <em>Vitellaria paradoxa</em> C.F. Gaertn. subsp. <em>nilotica</em> (shea tree) in Uganda. The study aimed at determining variations in germination among five shea tree seed provenances and seedling growth performance based on five growth traits (total height, root collar diameter, leaf length, leaf width and leaf petiole length). Five populations were considered from four agroecological zones comprising of 180 candidate “plus” trees. The seed trees consisted of 16 ethnovarieties selected based on their traits for fast growth and high oil yield. A total of 1,204 biological seeds were collected and sown in a tree nursery at Ngetta Zonal Agricultural Research and Development Institute during the month of June 2018 in a randomized incomplete block design with three replications. Significant variation (χ = 708;p < 0.01) was observed in seedling phenotypic traits within and between populations. Regression equation for height growth and leaf size index were given as y = 0.3787 + 12.671x and y = 0.6483 + 15.413x respectively. Root collar diameter was more correlated to leaf size index (0.425) than to height growth (0.30). Clustering of shea tree seedlings based on phenotypic growth traits revealed one aggregated cluster indicating that most of the seedlings from the five populations were similar (Jaccard index 0.92, p < 0.01). However, clustering based on SNP markers revealed three different populations. We recorded higher growth (χ = 708;p < 0.001) in Arua shea population. Red seeded;thin pulped and hairy fruited shea tree ethnovarieties recorded faster growth than the rest. The results reveal useful traits in selection for tree growth and further identified shea tree ethnovarieties that could be selected for fast growth.
