In vitro selection for wilt resistance in guava (Psidium guajava L.) cv. Allahabad Safeda

In vitro selection is a feasible method for developing wilt resistant or tolerant genotypes of guava. Unlike other crops, this approach has not been well established for guava. In vitro selection system against Fusarium wilt was employed with the aim to establish a recurrent selection system in guava (Psidium guajava L.) both at the cellular and plant level. In vitro somatic embryogenesis derived plantlets of guava cv. Allahabad Safeda were screened against Fusarium sp. culture filtrate atvarious concentrations of (0, 5, 25, 50 and 100%, v/v) supplemented in Murashige and Skoog (MS) basal liquid medium up to four selection cycles. The effect of Fusarium culture filtrate on plantlet survival and proliferation were observed to be directly related to the concentration in the selection media. The current study revealed that in vitro screening of guava plantlets using Fusarium sp. culture filtrate when exposed to the ten different culture filtrates at five concentrations of which; two of the culture filtrates oiFusarium solani (F2 and F15) shows maximum mortality of guava plantlets at 50% culture filtrate and later shows some level of tolerance to the culture filtrates. However, two of the culture filtrates F18 and F24 oiFusarium oxysporum f sp. psidii shows maximum regeneration i.e., up to 100% even after fourth selection cycle. Current study revealed that Fusarium sp. culture filtrate can be potentially employed as a potent selection agent for carrying out in vitro selection approach against wilt disease of guava. The successful recurrent selection system developed in vitro on the basis of current research can probably help in ameliorate the problem of wilt in guava.