Identification Of Ancestry And Assessment Of Resistance For The Intergeneric Hybridization BC₃F₁ Lines From Saccharum Officinarum×Erianthus Arundinaceus

The problems of drought,disease and single variety have limited the healthy,stable and sustainable development of sugarcane industry in China.These problems can be solved by breeding new sugarcane varieties which have higher resistance to drought and disease as well as better yield and quality.E.arundinaceus has the characteristics of strong resistance to disease,drought and pests,and excellent ratooning ability,and strong tolerance to environmental stresses.Excellent genes of E.arundinaceus have been introduced to sugarcane cultivars by the distant hybridization.It can broad the genetic basis of sugarcane,and breeding new sugarcane varieties which have higher resistance to drought and disease as well as excellent agronomic characteristics.YC73-226 and YC E06-111?BC₃of E.arundinaceus?were used as the crossing parents in this study.The E.arundinaceus ancestry of the intergeneric hybridization BC₃F₁ lines from S.officinarum×E.arundinaceus was identified by A lu-like PC R method.The resistance to drought and sugarcane smut disease caused by Sporisorium scitamineum of the BC₃F₁ lines with E.arundinaceus ancestry were evaluated.The excellent BC₃F₁ lines which have highly resistance to drought and sugarcane smut disease were selected.Which can lay the foundation for the future sugarcane breeding.The main results of this study are as follows:?1?The results of identification of E.arundinaceus ancestry showed that 83 hybrid offspring had E.arundinaceus ancestry from 87 selected offspring from a cross of S.officinarum with E.arundinaceus.The positive rate was 95.40%.?2?The results showed that 30 BC₃F₁ lines with E.arundinaceus ancestry and the control cultivar ROC22 under water stress at the elongation stage,sugarcane leaves of all lines had suffered different degrees of drought damage.Plant height,dry matter weight of shoot and root had appeared different degrees of reduce.Root activit ies had decreased gradually.The contents of soluble protein,soluble sugar,soluble proline,MDA and the activities of SOD,POD,C AT in sugarcane leaves had increased gradually.?3?The 31 tested lines were divided into three categorie s including strong drought resistance,moderate drought resistance and weak drought resistance through evaluated the drought resistance of 30 BC₃F₁ lines with E.arundinaceus ancestry and the control cultivar ROC22.ROC22 and 17 BC₃F₁ lines?56.67%?showed strong drought resistance,among which,3 lines?HE15-82,HE15-84 and HE15-72?were stronger than the control cultivar ROC22.10 BC₃F₁ lines?33.33%?showed moderate drought resistance.3 BC₃F₁ lines?10.00%?showed weak drought resistance.?4?The results of evaluation of resistance to sugarcane smut disease for 80 BC₃F₁ lines with E.arundinaceus ancestry indicated that 31 BC₃F₁ lines?38.75%?showed resistance to sugarcane smut disease,among which,26 BC₃F₁ lines?83.87%?were highly resistant to sugarcane smut disease.While 49 BC₃F₁ lines?61.25%?showed susceptible to sugarcane smut disease.?5?7 lines?HE15-82,HE15-72,HE15-17,HE15-23,HE15-62,HE15-46 and HE15-14?were selected as the excellent BC₃F₁ lines which were both highly resistant to drought and sugarcane smut disease.