To understand genetic structure and diversity of parental cultivars involved in China Mainland sugarcane breeding programs, 92 elite parents and 4 wild relatives were genotyped with 18 microsatellite DNA markers. The ...To understand genetic structure and diversity of parental cultivars involved in China Mainland sugarcane breeding programs, 92 elite parents and 4 wild relatives were genotyped with 18 microsatellite DNA markers. The genetic similarity （GS） values among the cultivars ranged from 0.346 to 0.960 with an average of 0.533. Among the introduced cultivars, India accessions had the closest genetic distance to China Mainland accessions （0.447）, while Australia accessions have the furthest distance （0.503）. A comparison of allelic diversity among geographical origins showed that there were 22 China Mainland specific alleles, of which 28% were derived from native S. spontaneaum germplasm in China. Model-based genetic structure, clustering, and principal components analyses consistently revealed there were five groups within the 96 accessions. Groups 1, 2, 4, and 5 consisted of all cultivars and group 3 only contained wild germplasm. Group 2 was characterized as the Introduction group with 46 cultivars predominantly introduced from Australia, Taiwan of China, India, and USA. Groups 1, 4, and 5 consisted of cultivars mostly originated from China Mainland, defined as the Complex group, Yacheng lines group, and F134/CP72-1210 group, respectively, upon their pedigree. By understanding the genetic relationships among the parental cultivars, breeders can gain a rational basis for expanding the gene pool and select the best parental accessions for crossing.展开更多
以污水厂冬季膨胀期污泥(SVI=280 m L·g^(-1))为对象,研究了臭氧投量对SBR系统污泥沉降性能及脱氮除磷效果的影响.结果表明,低浓度投加臭氧(0.085 g·g^(-1),以O3/MLSS计)20 d后,菌丝体被打断,SVI降至125 m L·g^(-1),消...以污水厂冬季膨胀期污泥(SVI=280 m L·g^(-1))为对象,研究了臭氧投量对SBR系统污泥沉降性能及脱氮除磷效果的影响.结果表明,低浓度投加臭氧(0.085 g·g^(-1),以O3/MLSS计)20 d后,菌丝体被打断,SVI降至125 m L·g^(-1),消除了污泥膨胀,且硝化、除磷效果不受影响.高浓度投加臭氧,污泥的沉降性能反而开始恶化,除磷效率也降至60%左右.进一步研究表明,PS/PN与SVI呈正相关关系(R^(2)=0.9381),可表征污泥的沉降性能;臭氧除打断菌丝体外,还通过改变EPS的含量及组分影响着污泥的沉降性能.展开更多
基金国家科技支撑计划项目(2007BAD30B00)广西区回国基金(桂科回0991011)+2 种基金广西自然科学基金(桂科基0639009)广西甘蔗分子遗传与品种改良研究重点实验室建设项目the USDA-ARS,Sugarcane Research Laboratory,Houma,LA,U.S.A.under a Non-funded Cooperative Agreement(USDA Control No.410334) between the Sugarcane Research Center,Chinese Academy of Agricultural Sciences,Nanning 530007 and the USDA-ARS,Sugarcane Research Laboratory,Houma,LA70360,U.S.A~~
基金supported by the National Natural Science Foundation of China (30800700)the China Agriculture Research System
文摘To understand genetic structure and diversity of parental cultivars involved in China Mainland sugarcane breeding programs, 92 elite parents and 4 wild relatives were genotyped with 18 microsatellite DNA markers. The genetic similarity （GS） values among the cultivars ranged from 0.346 to 0.960 with an average of 0.533. Among the introduced cultivars, India accessions had the closest genetic distance to China Mainland accessions （0.447）, while Australia accessions have the furthest distance （0.503）. A comparison of allelic diversity among geographical origins showed that there were 22 China Mainland specific alleles, of which 28% were derived from native S. spontaneaum germplasm in China. Model-based genetic structure, clustering, and principal components analyses consistently revealed there were five groups within the 96 accessions. Groups 1, 2, 4, and 5 consisted of all cultivars and group 3 only contained wild germplasm. Group 2 was characterized as the Introduction group with 46 cultivars predominantly introduced from Australia, Taiwan of China, India, and USA. Groups 1, 4, and 5 consisted of cultivars mostly originated from China Mainland, defined as the Complex group, Yacheng lines group, and F134/CP72-1210 group, respectively, upon their pedigree. By understanding the genetic relationships among the parental cultivars, breeders can gain a rational basis for expanding the gene pool and select the best parental accessions for crossing.
文摘以污水厂冬季膨胀期污泥(SVI=280 m L·g^(-1))为对象,研究了臭氧投量对SBR系统污泥沉降性能及脱氮除磷效果的影响.结果表明,低浓度投加臭氧(0.085 g·g^(-1),以O3/MLSS计)20 d后,菌丝体被打断,SVI降至125 m L·g^(-1),消除了污泥膨胀,且硝化、除磷效果不受影响.高浓度投加臭氧,污泥的沉降性能反而开始恶化,除磷效率也降至60%左右.进一步研究表明,PS/PN与SVI呈正相关关系(R^(2)=0.9381),可表征污泥的沉降性能;臭氧除打断菌丝体外,还通过改变EPS的含量及组分影响着污泥的沉降性能.
