Evaluation Of Populus Nigra L.Gene Resources For Breeding

As an important gene donor of many poplar varieties in the world, Populus nigra L. occurs in Asia and Europe and plays important roles in genetic improvement of poplars. Aigeiros gene resource is scarce in China (few Populus nigra L in the Altai Mountains). In order to enrich P. nigra L gene resource and to enlarge the genetic base for poplar breeding programs, a lot of P. nigra L gene resources have been introduced to China in recent years. Full understanding of P. nigra L gene resources would provide strong scientific evidence for poplar breeding. This paper comprehensively evaluates P. nigra L from foliage traits , growth, drought resistance and wood properties; and evaluates molecular genetic diversity by simple sequence repeats and single nucleotide polymorphism markers. By combining the results of wood properties and molecular markers, markers correlated with wood properties and growth were identified. The main results are described as follows: 1 , Evaluation on foliage traits and growth of P. nigra L. There are three types in foliage traits according to the shapes of leaf base: heart-shaped, truncated and cuneal respectively. Leaves with hart-shaped base have bigger leaf-area, leaf-area and growth can be estimated based on the shapes of leaf base; Great variation was found in leaf traits, the coefficient of variation of leaf-area reached to 43.61%; The top ten clones advantageous in growth ranked according to the comprehensive evaluation are respectively N23,N124, N31,N123, N117, N16, N52, N128, N5, N13. 2, Evaluation of water use efficiency of P. nigra L. Water use efficiency(WUE) of P. nigra L. was analyzed by stable carbon isotope techniques. The foliar δ 13C value of P. nigra L. varied significantly, ranging from -30.40‰ ±0.006‰ to -27.02‰±0.448‰, the gene resources introduced from east Europe and central Europe had high δ 13C value, indicating these resources had a higher WUE; The correlation analysis between δ 13C value and growth was also studied; The top ten clones advantageous in growth and WUE according to comprehensive evaluation are respectively N116,N51, N38,...