Spikelet sterility in rice genotypes affected by temperature at microsporogenesis/Esterilidade de espiguetas em genotipos de arroz irrigado afetada pela temperatura na microsporogenese

• Published in: Revista brasileira de engenharia agrícola e ambiental 2017-12, Vol.21 (12), p.817
• Main Authors: de Souza, Natalia M, Marschalek, Rubens, Sangoi, Luis, Weber, Francieli S
• Format: Article
• Language: English
• ISSN: 1415-4366
• DOI: 10.1590/1807-1929/agriambi.v21n12p817-821

This study evaluated the effect of temperatures during the phase of microsporogenesis on spikelet sterility of paddy rice and identified genotypes tolerant to low temperatures at this growth stage. The inbreds SC681, SC491, and SC676 and the cultivars Epagri 109 and SCS116 Satoru were assessed. The genotypes were submitted for three days in a growth chamber to five temperatures at microsporogenesis: 9, 12, 15, 18, and 21[degrees]C. For each tested temperature, a control was kept in the greenhouse under environmental conditions. After harvest, full and empty spikelets were counted and weighed and the percentage of spikelet sterility was determined. Data were evaluated by variance analysis using the F test. Averages were compared by Tukey's test and regression analysis. The highest spikelet sterilities were observed when the genotypes were exposed to the temperatures of 9 and 12[degrees]C. Genotype spikelet sterility was similar to that of the control at 21[degrees]C. The inbred SC 676 presented higher tolerance to lower temperatures is therefore potentially suited to generate a cultivar with adequate agronomic performance in rice growing areas prone to cold conditions at microsporogenesis. Key words: Oryza sativa booting cold controlled environment Este trabalho teve como objetivo avaliar o efeito da temperatura na fase de microsporogenese sobre a esterilidade de espiguetas de arroz irrigado identificando, nesta fase, genotipos tolerantes a baixas temperaturas. Foram testadas as linhagens SC681, SC491 e SC676 e as cultivares Epagri 109 e SCS116 Satoru. Os genotipos foram submetidos por tres dias em camara de crescimento a cinco temperaturas na microsporogenese: 9, 12, 15, 18 e 21[degrees]C. Para cada temperatura um tratamento testemunha foi mantido a temperatura ambiente na casa de vegetacao. Apos colheita realizaram-se a contagem e a pesagem das espiguetas cheias e vazias, determinando-se a percentagem de esterilidade. Os dados foram submetidos a analise de variancia pelo teste F. Quando significativas, as medias foram comparadas pelo teste de Tukey e analise de regressao. A maior esterilidade foi observada nos genotipos submetidos as temperaturas de 9 e 12[degrees]C. A esterilidade foi similar entre testemunhas e a 21[degrees]C. A linhagem SC676 apresentou maior tolerancia a ocorrencia de baixas temperaturas mostrando-se promissora para gerar uma cultivar com desempenho agronomico adequado, em regioes orizicolas propensas a ocorrencia de frio na microspor