煙草對氣候斑點病的抗性遺傳研究

Inheritance of tobacco resistance to weather- fleck

摘要: 選擇抗性不同的6 個烤煙基因型，采用P（×P- 1）/ 2 雙列雜交遺傳交配設計方法,，分析了煙草對氣候斑點病的抗性（病情指數(shù)）和氣孔導度的遺傳方式,。研究結果表明，煙草對氣候斑點病的抗性和氣孔導度大小均符合加性- 顯性遺傳模型,，抗病表現(xiàn)為隱性,，感病為顯性，氣孔導度大表現(xiàn)為顯性,，氣孔導度小表現(xiàn)為隱性,。配合力分析表明，感病品種RG17,、K326 具有較高的正向一般配合力（增加病指,、增大氣孔導度，表現(xiàn)感?。?，抗病品種NC89、中煙90 和中抗品種具有負向一般配合力（降低病指,，減小氣孔導度,，表現(xiàn)抗病）,。

Abstract: Six tobacco（ Nicotiana tabacum）genotypes were selected as the parents of P（×P- 1）/2 incomplete diallel cross to determine combing ability and genetic model of stomatal conductance on tobacco leaves and disease resistances to weather- fleck. The results showed that genetic characteristics of stomatal conductance on the lower epidermis of tobacco leaves and resistance to weather- fleck was of additive- dominance genetic models. Recessive genes controlled disease resistance and small stomatal conductance,，and dominant genes controlled disease susceptibility and big stomatal conductance. Susceptible genotypes possessed high positive GCA which was negative in resistant genotypes.