Abiotic stress tolerance in mango (Mangifera indica L.) rootstocks

Abstract

Mango (Mangifera indica L.) a tropical fruit crop with immense economic and cultural value, is extensively grown in a wide range of agro-climatic zones. Mango seedlings are resilient to a variety of environmental conditions, but they frequently face difficult obstacles due to abiotic stress factors. It is extremely concerning that this crop's productivity has been dropping over the last few years. Considering these problems into account, a study entitled “Abiotic Stress tolerance in mango (Mangifera indica L.) rootstocks” was carried out in the Department of Fruit Science during 2022-23, constituting three experiments namely, Screening of mango genotypes for tolerance to salinity, flooding and drought. All the set of three experiments were conducted using factorial completely randomized design (FCRD) with two factors: genotypes viz., V1- Moovandan, V2- Olour, V3- Kurukkan, V4- Chandrakaran, V5- Vellaikolumban, V6- Bappakai, V7- H-66, and abiotic stress. In the first experiment, mango genotypes were evaluated for different levels of salinity stress viz., S0- Control, S1- 2 dSm-1, S2- 4 dSm-1, S2- 4 dSm-1, and S4- 8 dSm-1 NaCl. Salinity was induced in the soil by quantifying the EC and pH of the soil. Growth characters had shown significant difference among genotypes. The highest seeding height (26.05 cm) was recorded in Moovandan, seeding girth (0.39 cm) was recorded in Bappakai, number of leaves (22.58), vigour index (2811.37), was observed in H-66, seedling girth (0.44 cm), number of sprouts (2.87) and internodal length (5.26 cm) in Chandrakaran. Physiological parameters further revealed that, leaf area (52.06 cm2) in Vellaikolumban. leaf area index (2.85) in H-66, Stomatal conductivity (0.127 molm-2s-1) and leaf transpiration rate (2.08 µmolm-2s-1) in Moovandan, net photosynthetic rate (6.74 µmolm-2s-1) in Olour recorded to maximum. On estimation of biochemical characters viz., phenol content and proline content was increased on increasing level of salinity. Higher phenol content (16.53 mg/g) and proline content (1.53 µmol/g) in was noticed in Bappakai. While, chlorophyll content (4.46 mg/g) was highest in Chandrakaran. Among the higher salinity stress Moovandan performed the