Obtenção de plantas de feijão-caupi resistentes ao Cowpea severe mosaic virus e ao Cowpea aphid-borne mosaic virus

Abstract

RESUMOPalavras-chave adicionais: Vigna unguiculata, Comovirus, Potyvirus, melhoramento genético.Among the viruses tha t infect cowpea ( Vign a u n gu ic u lata L . Walp.), Cowpea severe mosaic virus (CPSMV) and Cowpea aphidb o rn e mo saic v iru s (CABMV) a re highlighted for their severity a n d wid esp rea d o ccu rr enc e, respe cti vel y. T h ere for e, the a im of t h is st u d y wa s t o o b t a i n a nd e v a l u a t e c o wpe a pl a n t s sh o wi n g resist a nce to CPS MV a nd CABMV in order t o develop n ew a nd e sse n t i a ll y d er i v e d c u l t iv a r s. E i g ht c r o sse s we r e pe r fo r me d , fo llo wed by ba c k cro sse s, u si ng t he lin e T E 9 7 -3 0 9 G-9 a n d t he cu l tiva r Pa ta tiva a s re sista nt pa rent a l do nors, a nd the c u ltiv a rs BR3-Tracuateua, BRS-Urubuquara, BRS-Novaera, BRS-Guariba and Pretinho a s su sceptible pa rents. Generations F2 a nd F2 RC1 were challenged for resista nce by mechanically inocu lating CPSMV a nd CABMV isolates. In F2RC1 genera tions, besides resista nce, other Barros, G.B.; Nogueira, M.S.R.; Oliveira, C.R.R.; Freire Filho, F.R.;Ribeiro, V.Q.; Veiga, C.F.M.; Brioso, P.S.T.; Eiras, M. Obtaining cowpea plants resistant to Cowpea severe mosaic virus and Cowpea aphid-borne mosaic virus. Summa Phytopathologica, v.39, n.2, p.130-136, 2013. traits were evaluated: number of days to the beginning of flowering, pod length, nu mber of seeds.pod-1, weight of 100 seeds, and yield of seeds.plant-1. All F2 and F2RC1 individuals were analyzed by the  2 test a nd fit to the expected frequency of 15 susceptible plants: 1 plant resistant to both viruses. The means of resistant F2RC1 plants, from each backcross, were compared with the mean of their respective recurrent parent by the t-test and means of backcrosses were compared by the Scott-Knott test. Genetic va riability among back crosses was detected for all traits. All backcrosses were considered promising for obta ining essentia lly derived cu ltiva rs resista nt to CPSMV a nd CABMV, and the selected plants have characteristics that allow the selection of lines with highly productive grains of good commercial quality.Dentre os vírus que infectam o feijão-caupi (Vigna ung uiculata L. Wa lp.) desta ca m-se, respectiva mente, pela severidade e ampla ocorrência o Cowpea severe mosaic virus (CPSMV) e o Cowpea aphidborne mosaic virus (CABMV). Portanto, objetivaram-se, no presente tra balho, obter e ava liar plantas de feijão-cau pi com resistência ao CPSMV e ao CABMV, visa ndo a o desenvolvimento de cu ltivares essencia lmente deriva da s e novas cu ltiva res. Rea liza ra m-se oito cruzamentos seguidos de retrocruzamentos, utilizando a linhagem TE 9 7 -30 9 G-9 e a cu ltiva r Pa ta tiva como genitores resistentes, e a s cu ltivares BR3 -Tra cua teu a, BRS-Urubu qua ra, BRS-Novaera, BRSGuariba e Pretinho como genitores suscetíveis. As gerações F 2 e F 2 RC 1 foram desafiadas quanto à resistência por meio de inoculação mecânica com isolados do CPSMV e do CABMV. Nas gerações F 2 RC 1 , além da resistência for...

Selection of phenotypic traits and resistance to Cowpea severe mosaic virus and Cowpea aphid-borne mosaic virus in cowpea [Vigna unguiculata (L.) Walp.] seeds with rugose white coat

“…Four offspring were resistant to both viruses (P3, P12, P17, and P24) ( Table 6). This cross-resistance had been identified in other cowpea genotypes (Oliveira et al, 2012;Barros et al, 2013), but these genotypes are not correlated with the seed traits obtained in the present selection effort. Synergism between CPSMV and CABMV (Table 6) was also observed in parent plants G41, G42, and G43, which caused apical death in all these individuals.…”

“…The other offspring were highly resistant and did not express symptoms in the field evaluations. Several resistant cowpea strains have been identified (Lima et al, 1986;Barreto and Santos, 1999;Rocha et al, 2003;Oliveira et al, 2012;Barros et al, 2013), none of which presents the agronomic characters exhibited by the offspring selected in the present study. Four offspring were resistant to both viruses (P3, P12, P17, and P24) ( Table 6).…”

“…In Brazil, the Cucumber mosaic virus (CMV), the Cowpea aphid-borne mosaic virus (CABMV), the Cowpea severe mosaic virus (CPSMV), and the Cowpea golden mosaic virus (CPGMV) are the most important . However, CPSMV and CABMV stand out as the viruses that most significantly harm cowpea crops: the former due to the severity of the infections it causes, the latter because of its prevalence (Barros et al, 2013). CPSMV, of the Comovirus genus, Secoviridae family, is transmitted semi-persistently by insects of the Chrysomelidae family (Diabrotica speciosa and Cerotoma arcuata) (Costa et al, 1978).…”

“…Some genotypes have been characterized as immune to CABMV: TVu 379 (Lima et al, 1986), IT85F-2687 (Rocha et al, 2003), and TVu 966 (Oliveira et al, 2012). Studies carried out to obtain cowpea cultivars resistant to CPSMV and CABMV revealed that the resistance inherited against both viruses is monogenic recessive in character (Barros et al, 2013). This feature of the resistance pattern results from the absence of any given factor that is indispensable to viral replication or mobility inside the host (Hull, 2012).…”

Biological differences and unilateral cross-protection between biotypes of Cowpea aphid-borne mosaic virus

“…Bock (1973) reported the absence of symptoms in cowpea inoculated with virus isolates from the genus Potyvirus obtained from passion fruit. The CABMV-C isolates obtained from cowpea did not infect passion which is strong evidence that the causal agent of passion fruit woodiness does not infect cowpea (BARROS et al, 2013;NASCIMENTO, 2014;LIMA et al, 2015).…”