Assessment of new citrus hybrid rootstocks to salinity at the early seedling stage under greenhouse conditions
¹Unit research of Plant Breeding and Germplasm Conservation, National Institute for Agricultural Research (INRA), Kenitra, Morocco
²Laboratory of Plant, Animal, and Agro-Industry Productions, Ibn Tofail University, Kenitra, Morocco
*Correspondence: hamidbenyahia2002@yahoo.fr
Abstract:
The citrus industry in arid areas is largely constrained by the salinity of irrigation water and soil. This study was conducted to determine how six novel citrus hybrid rootstocks will respond to salinity at the seedling stage. Three different NaCl concentrations, 0, 2, and 5 g L-1, were added to the half-concentrated Hoagland solution (corresponding to 1.3 (control), 4 and 9 dS m-1, respectively). Three-month-old seedlings grown in greenhouse conditions and transplanted in plastic pots were used. After two months of stress, different responses from the rootstocks and salt levels were observed. The addition of NaCl to the irrigation solution considerably decreased the fresh and dry weight and leaf chlorophyll content. Additionally, the proline content, soluble sugar, and the leaf chloride content increase with the increase in salinity. Our findings demonstrated that the hybrid Poncirus Trifoliata× Citrus reshni Hort. ex Tan. (V5) H6 is salt-sensitive, accumulating a high leaf chloride level of 46.92 mg g-1 of dry matter and a low chlorophyll content of 1.12 mg g-1 of fresh matter associated with signs of leaf toxicity, leading to poor fresh and dry weight. Although hybrid Poncirus Trifoliata× Citrus reshni Hort. ex Tan. (V1) H2 is thought to be salt-tolerant, it accumulates 38.88 mg g-1 of dry-matter leaf chloride and 1.72 mg g-1 of fresh-matter chlorophyll content.
Key words:
chloride, citrus, hybrid rootstock, NaCl, salt stress