Evaluation on disease resistance of sugarcane family

ObjectiveThe present study aimed to understand the characteristics of disease resistance of sugarcane parents and hybrid combinations,and to provide reference and guidance for the selection of parents and hybrid progeny.MethodThe main agronomic traits and disease data of pokkahboeng,smut,leaf disease of plant seedlings,and pokkah-boeng data of ratoon sugarcane were investigated from 146 sugarcane families in 2015. Correlation analysis,variance and combining ability analysis were processed.ResultDisease of plant seedlings mainly occurred on leaf,including red rot, ring spot,brown streak,purple spot and yellow spot diseases. Incidence of pokkahboeng in ratoon sugarcane was signifi-cantly higher than that in new planting sugarcane. Correlation analysis showed that smut disease affected sugarcane yield in planting seedlings. There was extremely significant negative correlation between incidence of pokkahboeng and leaf disease(P<0.01,the same below). There was extremely significant difference in incidence of pokkahboeng,incidence of leaf disease and leaf disease among families. The traits contained low broad sense heritability. Both additive and non-addi-tive effects were present in the incidence of pokkahboeng ,but only additive effect were found in incidence of leaf disease and leaf disease selectable rate. In top 20 parents,leaf disease index had the highest breeding value,followed by pokkahboeng index,and leaf disease selectable rate had low breeding value. Evaluated by cross effects,families with good resistance to pokkahboeng,leaf disease and high leaf disease selectable rate were 87,74 and 50 respectively.ConclusionResistance to smut and pokkahboeng should not be evaluated by new plant seedling. Incidence or index of pokkahboeng can be selec-ted according to the environmental variation when evaluating the resistance of ratoon sugarcane to pokkahboeng.