Morphological and Molecular Marker Screening for Drought Tolerance in Egyptian Jew's Mallow (Corchorus olitorius L.) Landraces

Abstract

Drought is the most important abiotic stress that severely affects the growth and yield of crops. The current study aimed to evaluate seven Jew's Mallow landraces (collected from different locations of Egypt) for both their response to water deficit and the level of genetic diversity among them. The water regime conditions that based on either 95% or 60% field capacity (FC) were applied after 21 days from the sowing date. Some morphological traits were measured, and the genetic diversity was evaluated by using random amplified polymorphic DNA (RAPD) marker. The results showed that the landraces differed in their responses to water deficit. All the studied agro-morphological traits were reduced under the stress condition, as well as chlorophyll content was significantly reduced. Furthermore, all the landraces accumulated the highest value (4.29) of proline at 60% FC. According to some drought indices, L6 was the most tolerant for drought stress, followed by L4, L7 and L5, while L1 was the lowest one. On the other hand, a moderate level of polymorphism (58.6%) was detected and a highly range of similarity relationships (0.61 to 0.84) were observed. Furthermore, the RAPD dendrogram was able to discriminate among the genotypes according to both their geographical and their drought tolerance capacity. The superiority of some landraces under drought stress conditions especially L6 suggested that landraces could be a beneficial tool for Jew's Mallow improvement breeding programs.

Keywords

• drought
• ecotypes
• molokhiya
• rapd marker
• leafy vegetables