Combining Ability And Genetic Correlation For Main Agronomic Characters In Potato(Solanum Tuberosum L.)

Combining ablity,heterosis and correlation analysis were analyzed of 15 agronomic characters for potato(Solanum tuberosum L.) of 9 parents and 18 crosses derived from 3×6 incomplete dialled cross in first clonal generation.The results indicated:(1) There are differences in different parents to every character on general combini- ng ability effective value,and there are differences in same parents to different charac- ter on general combining ability effective value.This difference offer possibility to id- entify and choose fine varieties.The same character's special combining ability effect- ive value vary with different crosses,and the same crosses vary with different charact- ers.This difference offer possibility to identify and choose fine crosses.(2) There are all certain heterosis in 15 characters,the amount of single tuber weight, rotten potato rate and tuber yield have bigger positive heterosis over mid-parent,tuber number has smaller positive heterosis over mid-parent and has negative heterosis over mid-parent trend.The order of heterosis over mid-parent is rotten potato rate>tuber yi- eld>tuber number>starch content>single tuber weight>tuber shape>large and medium -sized potato rate>tuber appearance>tuber habit.The order of the heterosis over high- parent is tuber number>single tuber weight>tuber yield>large and medium-sized potat o rate>tuber appearance>rotten potato rate>starch content>tuber shape>tuber habit.(3) Plant vigor and tuber number are main effective factors to starch content.For developing amount of starch content,the plant vigor and tuber number should be deve- loped because they have bigger positive straight effects,and the both characters have significant positive correlation,but the large and medium-sized potato rate and rotten potato rate should be reduced.So,on potato(Solanum tuberosum L.) with high starch content breeding,plant vigor and tuber number may regard as main characters choice indexes,and pay attention to large and medium-sized potato rate and rotten potato rate. Single tuber weight and tuber number are main effective factors to tuber yield.For de- veloping amount of tuber yield,the single tuber weight and tuber number should be developed because they have bigger positive straight effects,and the both characters have significant impositive correlation,but the tuber habit should be reduced.So,on potato(Solanum tuberosum L.) tuber yielding breeding,single tuber weight and tuber number may regard as main characters choice indexes,but the tuber habit.