ABSTRACT It is well known that phytochromes mediate a wide range of photomorphogenic processes in plants. In addition, many studies have demonstrated the involvement of phytochromes as part of abiotic stress signaling responses. However, little is known about cadmium (Cd) stress regulation by phytochromes. Thus, in this study, we used the phyA (far red-insensitive; fri), phyB1 (temporary redinsensitive; tri) and phyB2 (phyB2) tomato (Solanum lycopersicum L.) mutants to investigate the roles of these three phytochromes on Cd stress responses. The plants were grown over a 21-d period in the presence of Cd. We evaluated plant growth, Cd and chlorophyll content and anatomical changes in the leaves. The results indicated that all genotypes were affected by Cd and showed reduced growth of the shoots and roots, as well as reduced chlorophyll content. The accumulation of Cd was similar for all genotypes, and a higher Cd content was found in roots. Anatomical analysis of the vascular bundles revealed that fri and tri seem to be more disrupted by Cd. Overall, these results indicate that phytochromes do not determine Cd stress tolerance in tomato plants.

Devido aos poucos estudos realizados com enxertias em melão rendilhado, visando um maior controle de patógenos do solo, este trabalho teve por objetivo avaliar 16 genótipos de cucurbitáceas quanto à resistência a Meloidogyne incognita e a compatibilidade da enxertia do melão rendilhado. Foram avaliados 16 acessos de cucurbitáceas: Benincasa hispida, Bucha, Abóbora 'Jacarezinho', Abóbora 'Menina Brasileira', Moranga 'Exposição', Moranga 'Coroa', Abóbora 'Canhão Seca', Abóbora 'Squash', Mogango 'Enrrugado Verde', Abóbora 'Mini Paulista', Abóbora 'Goianinha', Melancia 'Charleston Gray', Melão 'Rendondo Gaúcho', Melão 'Redondo Amarelo', Pepino 'Caipira HS' e Pepino 'Caipira Rubi', quanto à resistência ao nematóide M. incognita, com base no fator de reprodução (FR), segundo Oostenbrink (1966). Para avaliação da resistência, as mudas foram transplantadas para vasos de cerâmica e foram aplicados 300 ovos ou juvenis de segundo estádio/mL de M. incognita, num total de 10 mL por vaso. Aos 50 dias após o transplantio, as plantas foram removidas dos vasos e realizou-se a avaliação da resistência. Para a compatibilidade entre os porta-enxertos resistentes e enxerto de melão rendilhado, foram realizadas enxertias do tipo garfagem fenda simples, em híbrido comercial de melão rendilhado de grande aceitação comercial e suscetíveil a M. incognita (Bônus N° 2). Os genótipos Bucha, Abóbora 'Goianinha', Abóbora 'Mini-Paulista', Melão 'Redondo Amarelo', Melancia 'Charleston Gray', foram resistentes ao nematóide M. incognita. As melhores compatibilidades ocorreram com os porta-enxertos Melão 'Amarelo', o qual teve 100% de pegamento, seguido da Abóbora 'Mini-Paulista' com 94%. Já Bucha, Melancia 'Charleston Gray' e Abóbora 'Goianinha', tiveram baixas porcentagens de pegamento: 66%, 62% e 50% respectivamente.

Due to the few studies about grafting in net melon, in order to obtain better control of soil pathogens, the aim of the present study was to evaluate 16 genotypes of Cucurbitaceae: Benincasa hispida, Luffa cylindrica, pumpkin 'Jacarezinho', pumpkin 'Menina Brasileira', squash 'Exposição', squash 'Coroa', pumpkin 'Canhão Seca', pumpkin 'Squash', pumpkin 'Enrrugado Verde', pumpkin 'Mini Paulista', pumpkin 'Goianinha', watermelon 'Charleston Gray', melon 'Rendondo Gaucho', melon 'Redondo Amarelo', cucumber 'Caipira HS' and cucumber 'Caipira Rubi', regarding to compatibility of grafting in net melon and resistance to Meloidogyne incognita, based on the reproduction factor (RF), according to Oostenbrink (1966). To assess resistance, the seedlings were transplanted to ceramic pots and inoculated with 300/mL eggs and/or second stage juveniles of M. incognita. At 50 days after transplanting, the plants were removed from the pots and the resistance was evaluated. The compatibility between resistant rootstock and grafts of net melon was determined by performing simple cleft grafting, in a commercial net melon hybrid of great market acceptance and susceptible to M. incognita (Bonus no. 2). The genotypes Luffa cylindrica, pumpkin 'Goianinha', pumpkin 'Mini-Paulista', melon 'Redondo Amarelo', watermelon 'Charleston Gray' are resistant to the nematode M. incognita. The better compatibilities occurred with the rootstocks melon 'Amarelo', which presented 100% of success, followed by pumpkin 'Mini-Paulista' with 94%. On the other hand, Sponge gourd, watermelon 'Charleston Gray' and pumpkin 'Goianinha' showed low graft take percentages of 66%, 62% and 50%, respectively.