Use of a detached leaf screening method for segregating Colorado potato beetle (Leptinotarsa decemlineata Say) resistant Solanum hybrid lines

Abstract

S. 2008. Use of a detached leaf screening method for segregating Colorado potato beetle (Leptinotarsa decemlineata Say) resistant Solanum hybrid lines. Can. J. Plant Sci. 88: 633Á638. A diploid segregating population for resistance to Colorado potato beetle (CPB) was developed by crossing the resistant Mexican species Solanum pinnatisectum (S. pnt., 2n 02x024) with the susceptible S. cardiophyllum (S. cph., 2n 0 2x 024). A resistant hybrid plant from this cross was selected and backcrossed as a female to S. cph in order to generate a backcross family. A beetle feeding preference test bioassay was developed to examine segregation for CPB resistance in 345 backcross progeny. A screening method that optimized the length of the feeding period allowed the quantification of CPB resistance in the backcross progeny. Percent resistance of the test lines over the susceptible control was determined using the formulawhere C and L indicated the amount of damage to the control and test line, respectively, in each Petri dish. All backcross progeny showed an acceptable normal distribution only after 4 and 8 h of feeding. The expression of resistance in the backcross population for this study varied not only among the progeny, but also was influenced by duration of exposure to CPB. A x 2 test of 1R:3S ratio of the 8-h data indicated that CPB resistance was controlled by two genes. Of the five feeding time exposures (4, 8, 12, 20 and 24 h) used in this study, the 8-h exposure was shown to be the optimal time for evaluating resistance to CPB in our potato hybrids.Key words: Colorado potato beetle, choice test, resistant potato, resistance screening method Nandy, S., Chen, Q., Yang, J., Beasley, D., Li, H. et Goettel, M. S. 2008. Se´gre´gation de ligne´es hybrides de Solanum re´sistantes au doryphore de la pomme de terre (Leptinotarsa decemlineata Say) au moyen d'une technique par feuille de´tache´e. Can. J. Plant Sci. 88: 633Á638. Les auteurs ont cre´e´une population diploı¨de re´sistante au doryphore de la pomme de terre (DP) par se´gre´gation en croisant l'espe`ce mexicaine re´sistante Solanum pinnatisectum (S. pnt., 2n 02x 024) avec la varie´teś ensible S. cardiophyllum (S. cph., 2n 02x024). Ils ont ensuite se´lectionne´un hybride re´sistant qu'ils ont re´trocroise´avec les organes maˆles de S. cph afin d'obtenir une famille re´currente. Les auteurs ont mis au point un essai biologique pour e´tudier la pre´fe´rence des cole´opte`res et pre´ciser la se´gre´gation de la re´sistance au DP chez 345 plants de deuxie`me ge´ne´ration. Une me´thode de se´lection optimisant la dure´e de la pe´riode d'alimentation du DP a permis de quantifier la re´sistance des plants. Les auteurs ont calcule´le degre´de re´sistance des ligne´es expe´rimentales par rapport au te´moin sensible graˆce a`la formuleou`les valeurs C et L correspondent respectivement a`l'importance des dommages cause´s a`la varie´te´te´moin et a`la ligne´e expe´rimentale, dans les boıˆtes de Pe´tri. La proge´niture des re´trocroisements ne re´ve`le une distribution normale a...

Managing the Colorado potato beetle; the need for resistance breeding

“…There are some methods, which can be used to test the CPB more easily. Laboratory-based methods, such measuring leaf consumption by adult CPB in petri dishes (Nandy et al 2008;Cooper et al 2009), suppression of larval survival and inhibition of larval growth on detached leaves (Lorenzen et al 2001;Cooper et al 2009) can be good methods for evaluation of CPB resistance in potato as long as they reflect the resistance expressed in the field. Several rearing methods for CPB have been established to support the lab-based evaluation method (Gelman et al 2001;Thorpe and Bennett 2003).…”

Potato Resistance Against Insect Herbivores

“…The genetics of resistance to the CPB in S. pinnatisectum was studied using a resistant 2n hybrid population with S. cardiophyllum (Chen et al 2004) and revealed that only two genes are responsible for resistance in S. pinnatisectum (Nandy et al 2008). Interspecific somatic hybrids between S. tuberosum and S. pinnatisectum were regenerated following electrofusion of mesophyll protoplasts (Thieme et al 1997;Chen et al 2008) and some of that material has been developed to the BC 4 stage (R. Thieme, pers.…”

“…Interspecific somatic hybrids between S. tuberosum and S. pinnatisectum were regenerated following electrofusion of mesophyll protoplasts (Thieme et al 1997;Chen et al 2008) and some of that material has been developed to the BC 4 stage (R. Thieme, pers. comm.…”

“…This amount of foliage could be more easily attained from plants grown from tubers in the field but requires an extra year to produce the tubers. The influence of test duration on results has also been studied (Nandy et al 2008). It was concluded that 8 hours was optimal because it produces a clearer genetic model of the plant resistance traits.…”

“…Solanum species have consequently been assigned endosperm balance numbers based on their ability to hybridize with each other (Jansky et al 2009). Furthermore, somatic hybridization can be used to overcome the lack of compatibility between wild and cultivated potatoes (Chen et al 2008).…”