Identification And Evaluation Of Sugarcane Germplasm Resources

Sugarcane is the most important sugar crop in China.Sugar yield accounts for90% of the national sugar output.Germplasm resources are the basis and guarantee of sugarcane hybrid breeding.The identification and evaluation of sugarcane germplasm resources can provide important support for allocating sugarcane hybrid combinations and improving breeding efficiency.In this paper,the important agronomic traits,resistance loci and sucrose phosphate synthase(SPS)of some important sugarcane breeding materials were analyzed,and the excellent genetic resources were discovered.The results are as follows:In this study,the reported brown rust resistance loci Bru1 and orange rust resistance loci G1 were used to analyze the parent resources and innovative materials in Sugarcane Breeding in China.Among 164 materials,23 materials with Bru1 resistance markers,including 07-913,02-281 and 05-352,were detected,accounting for 14% of the tested materials.Among 180 materials,10 materials with G1 locus of orange rust resistance,such as Yuetang 96-86,Guitang 03-8 and Gannan 81-1035,were detected,accounting for 5.56% of the tested materials.Six accessions of Yuetang96-86,ROC16 and ROC22 had both Bru1 and G1 loci,which might be resistant to brown rust and orange rust.In this study,the agronomic traits of 25 important parents in sugarcane breeding were evaluated.The results showed that the Brix of 8 new varieties was higher than that of control varieties ROC22,and the Brix of perennial roots of 18 varieties was higher than that of control varieties ROC22.The grey correlation analysis method was used to analyze the correlation degree of plant height,stem diameter,Brix and tillering rate.The correlation degree between the tillering rate of sugarcane and its traits is in the order of plant height > stem diameter > Brix > sugar content,which reflects the primary and secondary relationship between the effects of sugarcane traits on the tillering rate of sugarcane.Because sugarcane is harvested from sugarcane stalks,tillering traits are particularly important for clonal sugarcane.In addition to yield,sugar content of sugarcane is also an important breeding objective of good varieties.Selecting germplasms with high yield and sugar content is the basis of breeding varieties with high yield and sugar content.Sucrose is the most important target product of sugarcane.Sucrose phosphatesynthase(SPS)is one of the key enzymes in sucrose synthesis.In this study,the full length of the coding region of sugarcane SPS IV gene and the full length of the ScSPS IV gene coding region 2943 BP encoding 981 amino acids were obtained by electronic cloning using part of the DNA sequence of the cloned sugarcane SPS IV gene as a probe.The gene has high homology with sorghum and maize sucrose phosphate synthase genes.It will provide a basis for further molecular cloning,functional verification and application of ScSPS IV gene.