ABSTRACT Late blight (Phytophthora infestans) is a serious problem in potato crops in southern Brazil due to favorable climatic conditions for the development of the pathogen and the lack of resistant cultivars available in the market. Thus, this study aimed to evaluate the reaction of eight cultivars (Asterix, Catucha, BRS Clara, BRS F63 - Camila, Cristal, BRS F183 - Potira, Markies, and BRS Pérola) and five advanced clones (F05-11-03, F21-07-09, Odone 80-02, F50-08-01, and F63-10-07) to late bight under field conditions. The Agata and the clone CIP392.617-54 were used as susceptible and resistant controls, respectively. The experiments were conducted in the municipality of Pelotas, RS, in the autumn season of 2018 and 2019. Sixty days after planting, the plants were inoculated with the pathogen; and, after one week, the genotypes were evaluated for disease severity and the area under the disease progress curve. ‘Catucha’ was classified as resistant to moderately resistant to P. infestans; ‘Cristal,’ F50-08-01 and ‘BRS Perola’, moderately susceptible to resistant; and ‘BRS F63’ - Camila, F63-10-07, F05-11-03, Asterix, F21-07-09, BRS F183 - Potira, and Odone 80-02, moderately susceptible to susceptible. BRS Clara and Markies showed the greatest variations in both experiments, showing to be susceptible in the autumn of 2018 experiment and moderately resistant in the autumn of 2019 experiment. Phytophthora infestans market Thus Asterix (Asterix Catucha F F6 Camila Cristal F18 Potira Pérola F051103, F051103 F05 11 03, 03 (F05-11-03 F210709, F210709 F21 07 09, 09 F21-07-09 8002, 8002 80 02, 02 80-02 F500801, F500801 F50 08 01, 01 F631007 10 F63-10-07 CIP392.61754 CIP39261754 CIP CIP392.617 54 CIP392 617 CIP392.617-5 controls respectively Pelotas RS 201 planting week curve ‘Catucha P ‘Cristal, F50-08-0 Perola, Perola , Perola’ F631007, 07, F05-11-03 F1 F05110 F0 1 0 (F05-11-0 F21070 F2 F21-07-0 800 8 80-0 F50080 F5 F63100 F63-10-0 61754 CIP392.6175 CIP3926175 CIP392617 CIP392.61 5 CIP39 61 CIP392.617- 20 ‘Cristal F50-08- F05-11-0 F0511 (F05-11- F2107 F21-07- 80- F5008 F6310 F63-10- 6175 CIP39261 CIP392.6 CIP3 6 2 F50-08 F05-11- F051 (F05-11 F210 F21-07 F500 F631 F63-10 CIP3926 CIP392. F50-0 F05-11 (F05-1 F21-0 F63-1 F50- F05-1 (F05- F21- F63- F05- (F05 (F0 (F
RESUMO A requeima (Phytophthora infestans) constitui-se em um sério problema à cultura da batata na região sul do Brasil em função das condições climáticas favoráveis ao desenvolvimento do patógeno e pela carência de cultivares resistentes disponíveis no mercado. Dessa forma, foi objetivo deste estudo, avaliar a reação de oito cultivares (Asterix, Catucha, BRS Clara, BRS F63 - Camila, Cristal, BRS F183 - Potira, Markies e BRS Pérola) e cinco clones avançados (F05-11-03, F21-07-09, Odone 80-02, F50-08-01 e F63-10-07) de batata à requeima em condições de campo. A cultivar Agata e o clone CIP392.617-54 foram utilizados como testemunhas, suscetível e resistente, respectivamente. Os experimentos foram conduzidos no município de Pelotas, RS, nos cultivos de outono de 2018 e 2019. Sessenta dias após o plantio, as plantas foram inoculadas com o patógeno e, decorrido uma semana, os genótipos foram avaliados quanto à severidade da doença e a área abaixo da curva do progresso da doença. ‘Catucha’ comportou-se como resistente a moderadamente resistente; ‘Cristal’, F50-08-01 e ‘BRS Pérola’, moderadamente suscetível a resistente; e ‘BRS F63’ - Camila, ‘F63-10-07’, ‘F05-11-03’, ‘Asterix’, ‘F21-07-09’, ‘BRS F183’ - Potira Odone 80-02, moderadamente suscetível a suscetível. As cultivares BRS Clara e Markies apresentaram as maiores variações em ambos experimentos, comportando-se como suscetível no outono de 2018 e moderadamente resistente no outono de 2019. Phytophthora infestans constituise constitui se mercado forma estudo Asterix, Asterix (Asterix Catucha F F6 Camila Cristal F18 Pérola F051103, F051103 F05 11 03, 03 (F05-11-03 F210709, F210709 F21 07 09, 09 F21-07-09 8002, 8002 80 02, 02 80-02 F500801 F50 08 01 F50-08-0 F631007 10 F63-10-07 campo CIP392.61754 CIP39261754 CIP CIP392.617 54 CIP392 617 CIP392.617-5 testemunhas respectivamente Pelotas RS 201 2019 plantio semana ‘Catucha comportouse comportou ‘Cristal, ‘Cristal , ‘Cristal’ Pérola, Pérola’ ‘F631007, ‘F63 ‘F63-10-07’ ‘F051103, ‘F05 ‘F05-11-03’ ‘Asterix, ‘Asterix ‘Asterix’ ‘F210709, ‘F21 ‘F21-07-09’ comportandose comportando F1 F05110 F0 1 0 (F05-11-0 F21070 F2 F21-07-0 800 8 80-0 F50080 F5 F50-08- F63100 F63-10-0 61754 CIP392.6175 CIP3926175 CIP392617 CIP392.61 5 CIP39 61 CIP392.617- 20 ‘F631007 ‘F6 ‘F63-10-07 ‘F051103 ‘F0 ‘F05-11-03 ‘F210709 ‘F2 ‘F21-07-09 F0511 (F05-11- F2107 F21-07- 80- F5008 F50-08 F6310 F63-10- 6175 CIP39261 CIP392.6 CIP3 6 2 ‘F63100 ‘F ‘F63-10-0 ‘F05110 ‘F05-11-0 ‘F21070 ‘F21-07-0 F051 (F05-11 F210 F21-07 F500 F50-0 F631 F63-10 CIP3926 CIP392. ‘F6310 ‘F63-10- ‘F0511 ‘F05-11- ‘F2107 ‘F21-07- (F05-1 F21-0 F50- F63-1 ‘F631 ‘F63-10 ‘F051 ‘F05-11 ‘F210 ‘F21-07 (F05- F21- F63- ‘F63-1 ‘F05-1 ‘F21-0 (F05 ‘F63- ‘F05- ‘F21- (F0 (F