1- Department of Horticultural Science, Tarbiat Modares University (TMU)
2- Department of Horticultural ScienceTarbiat Modares University (TMU) , arzani_k@modares.ac.ir
3- Department of Agronomy, Tarbiat Modares University (TMU)
4- Temperate Fruits Research Center, Horticultural Science Research Institute (HSRI),
Abstract: (395 Views)
The effect of drought stress and the rootstock with different root systems, on gas exchange, macronutrient uptake, and use, and osmolytes were assessed on two-years-old seedlings of two pears (Pyrus communis L.) cultivars, `Dargazi᾿ and `Louise Bonne᾿ grafted onto `Dargazi᾿ seedlings and `Pyrodwarf᾿ clone rootstocks. Treatments were control (100%), moderate (60%), and severe drought (30% FC). Growth characteristics, LRWC, gas exchanges, stomatal morphology, soluble protein, proline, glycine betaine and total soluble carbohydrate, leaf and root macronutrients, and other nutrient use efficiency parameters were measured. Results showed that root-to-shoot ratio, LRWC, SP, photosynthetic nitrogen use efficiency, leaf osmotic potential (Ψs), leaf potassium, root calcium , root nitrogen, stomatal aperture, and gas exchange traits such as net photosynthetic rate, transpiration rate, stomatal conductance (gs), instantaneous carboxylation efficiency of Rubisco, of all scion-rootstock combinations decreased. In addition, Prol, GB, TSC, root potassium, leaf calcium, LN, LP, and root phosphorus were increased under drought. When subjected to the severe stress level, `Dargazi᾿ showed better instantaneous water use efficiency, LN, LNO3−, and LNH4+, Prol, and Ψs contents, nitrogen utilization efficiency, and nitrogen uptake efficiency, when used as the cultivar or rootstock. While `Louise Bonne᾿ had higher amounts of R/SH ratio, total nitrogen accumulation, leaf and root NRA, An, intracellular CO2 concentration (Ci), E, and root nitrate under moderate stress levels. The present obtained results suggested that under severe stress levels, `Dargazi᾿ showed better resistance as the seedling rootstock or cultivar, and `Pyrodwarf᾿ clonal rootstock and `Louise Bonne᾿ cultivar had better response under moderate stress conditions.
Article Type:
Original Research |
Subject:
Plant Breeding and Genetics Received: 2023/07/30 | Accepted: 2024/01/11 | Published: 2024/03/31