Comparative study of the floral biology and of the response of productivity to insect visitation in two rapeseed cultivars no Rio Grande do Sul

• Published in: Brazilian journal of biology Vol. 74; no. 4; p. 787
• Main Authors: Blochtein, B, Nunes-Silva, P, Halinski, R, Lopes, L.A, Witter, S
• Format: Journal Article
• Language: English
• Published: Association of the Brazilian Journal of Biology 01.11.2014
• Subjects: Brasil
• ISSN: 1519-6984; 1678-4375
• DOI: 10.1590/1519-6984.02213

Planning the artificial pollination of agricultural crops requires knowledge of the floral biology and reproductive system of the crop in question. Many studies have shown that rapeseed (Brassica napus Linnaeus) is self-compatible and self-pollinated, but its productivity may be increased by insect visitation. In the present study, the floral biology and the response of productivity to insect visitation of two rapeseed cultivars (Hyola 420 and Hyola 61) were analyzed and compared in three regions of Rio Grande do Sul, Brazil. The rapeseed flowers presented three stages during anthesis, with the time periods varying between the cultivars. Both cultivars are self-compatible, but free visitation of insects increased productivity by 17% in the Hyola 420 cultivar and by approximately 30% in the Hyola 61 cultivar. Therefore, it is concluded that the cultivar Hyola 61 is more dependent on insect pollination than Hyola 420. Keywords: floral biology, reproductive system, pollination, rapeseed, Brassica napus. O planejamento de polinizacao dirigida nas culturas agricolas requer o conhecimento da biologia floral e do sistema reprodutivo da cultura em questao. Muitos estudos mostram que a canola (Brassica napus Linnaeus) e auto compativel e auto polinizada, no entanto, sua produtividade pode ser aumentada pela visita por insetos. Nesse estudo, a biologia floral e a resposta da produtividade a visita por insetos de duas cultivares de canola (Hyola 420 e Hyola 61) foram analisadas e comparadas em tres regioes do Rio Grande do Sul, Brasil. As flores de canola apresentaram tres fases durante a antese, havendo variacao no periodo de tempo de acordo com a cultivar. Ambas as cultivares sao auto compativeis, mas a livre visita por insetos aumentou a produtividade em 17% na cultivar Hyola 420 e cerca de 30% na cultivar Hyola 61. Dessa maneira, concluimos que a cultivar Hyola 61 e mais dependente da polinizacao entomofila que a Hyola 420. Palavras-chave: biologia floral, sistema reprodutivo, polinizacao, canola, Brassica napus.