Mehdi Oraei; Seyyed Jalal Tabatabaie; Esmaeil Fallahi; Ali Imani; Leila S. Fatemy
Abstract
Boron (B) toxicity is an important disorder that can limit plant growth in arid and semi-arid environments. It has been proven that use of tolerant rootstocks impede B uptake or transport to the aerial portions of plants. This may alleviate B toxicity in the scion, consequently improves the tolerance ...
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Boron (B) toxicity is an important disorder that can limit plant growth in arid and semi-arid environments. It has been proven that use of tolerant rootstocks impede B uptake or transport to the aerial portions of plants. This may alleviate B toxicity in the scion, consequently improves the tolerance to excess B in the root zone. An experiment was conducted to find the effects of B toxicity on vegetative growth, physiological characteristics and B distribution of almond tree (Prunus dulcis Mill.) cv. “Ferragnes” grown in the controlled environment. Three levels of B (0.25, 10, 20 mg/L) from H3BO3 and two almond rootstocks (GF677, Tuono) were factorially combined in a completely randomized design with four replications. The results showed that B toxicity had significant effects on vegetative growth, physiological characteristics and B distribution in almond tree. With increasing B levels in nutrient solution, vegetative characteristics including leaf production percentage and main shoot elongation was decreased significantly. However, Fr/Tuono was affected less than Fr/GF677. Also, physiological characteristics such as electrolyte leakage percentage, proline content and leaf necrosis percentage were increased significantly in two scion-rootstock combinations. On the basis of these results, GF677 because of an inability to restrict uptake and/ or transport of excess B from root system to aerial parts of scion, have a higher sensitivity to B toxicity. Instead, Tuono via mechanism of preferential distribution of B in roots inhibited the accumulation of high concentration of B either in young leaves or meristematic tissues partially and protected these susceptible organs against injury caused by B toxicity. In conclusion, it seem that under excess B conditions Tuono rootstock have higher tolerance than GF677.
Mehdi Oraei; Seyyed Jalal Tabatabaie; Esmaeil Fallahi; Ali Imani
Abstract
Abstract
Salinity tolerance is one of the major factor influencing crop productivity in arid and semi-arid areas. The salinity tolerance of fruit trees can be enhanced through the use of tolerant rootstocks. This experiment was conducted to investigate the effects of salinity stress and rootstock on ...
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Abstract
Salinity tolerance is one of the major factor influencing crop productivity in arid and semi-arid areas. The salinity tolerance of fruit trees can be enhanced through the use of tolerant rootstocks. This experiment was conducted to investigate the effects of salinity stress and rootstock on the growth, photosynthetic rate and nutrient concentrations of almond (Prunus dulcis Miller.) cv. “Ferragnes” grown in the soilless culture and controlled environment. Three levels of NaCl (0, 50, 100 mM) and two rootstock (GF677, Tuono) was factorially combined in a randomized complete block design with four replications. The results showed that the salinity stress had a significant diminish effects on vegetative and physiological characteristics and nutrient concentrations of almond. The severity of the adverse effects of salinity varied among rootstocks. Fresh and dry weights of leaf and root, leaf number and chlorophyll index was increased in F/GF677 at 50 mM salinity level and then decreased compare to that in control, however it was decreased at 100 mM salinity concentration in F/Tuono. Photosynthetic rate, leaf area and K/Na ratio was decreased with increasing salinity in both rootstocks, it became more pronounced in F/Tuono. With increasing NaCl levels, leaf concentrations of N, P, K was decreased and Na concentration was increased in both rootstocks. This results imply that GF677 have a exclusion mechanism such as restrict either the uptake or transport of Na from root to shoot or maintain sufficient level of K, have a higher salt tolerance than Tuono hence, under salinity conditions can be useful salt-tolerant rootstock for different almond cultivars.
Key words: Almond, Rootstock, Salinity tolerance, Salinity stress, Photosynthesis
