Phenotypic characterization of papaya genotypes to determine powdery mildew resistance

Abstract In support of breeding of papaya (Carica papaya), the disease incidence and severity of powdery mildew (Ovulariopsis caricicola) were evaluated in papaya genotypes. Two experiments in complete randomized blocks were carried out, one in the field and the other in a greenhouse. In field experiments, the lowest mean disease incidence was observed on the genotypes ‘Costa Rica’ and ‘Baixinho Super’, and the lowest mean disease severity on ‘Caliman M5’, ‘GTF’, ‘SH 11-08’, and ‘JS 11’. In the greenhouse experiment, the genotypes ‘Caliman M5’, ‘Golden’, ‘Kapoho Solo’, ‘Waimanalo’, ‘Mamão Bené’, ‘SH 12-07’, ‘JS 12’, and ‘GTF’ had the lowest mean incidence in at least one evaluation. On the other hand, for severity, the genotypes ‘Diva’, ‘Sunrise Solo 72/12’, ‘Kapoho Solo PA’, ‘Waimanalo’, ‘Maradol’, ‘Maradol GL’, ‘SH 15-04’, ‘FMV, ‘JS 12-4’, ‘SH 12-07’ and ‘Sekati FLM’ had the lowest means. These results indicate these genotypes for a possible use in breeding for reduction of powdery mildew intensity.

摘要：为支撑番木瓜（Carica papaya）的育种工作，本研究针对不同番木瓜基因型的番木瓜白粉病（Ovulariopsis caricicola）发病率与病情严重度开展评价。本研究设置两项完全随机区组试验，分别于田间与温室环境下进行。田间试验结果显示，基因型‘哥斯达黎加（Costa Rica）’与‘贝西尼奥超级（Baixinho Super）’的平均病害发病率最低；而‘Caliman M5’、‘GTF’、‘SH 11-08’及‘JS 11’的平均病情严重度最低。温室试验中，‘Caliman M5’、‘Golden’、‘Kapoho Solo’、‘Waimanalo’、‘Mamão Bené’、‘SH 12-07’、‘JS 12’及‘GTF’等基因型在至少一次评估中的平均发病率最低。而就病情严重度而言，‘Diva’、‘Sunrise Solo 72/12’、‘Kapoho Solo PA’、‘Waimanalo’、‘Maradol’、‘Maradol GL’、‘SH 15-04’、‘FMV’、‘JS 12-4’、‘SH 12-07’及‘Sekati FLM’等基因型的平均严重度最低。上述结果表明，这些基因型可应用于降低番木瓜白粉病发生强度的育种研究中。