Effect of laser priming on canola yield and its components under salt stress

Abstract

A b s t r a c t. The effect of laser priming at different irradiation times on canola yield and its components under saline conditions were investigated. The results showed that laser priming had a positive effect on yield and its components and caused yield increase under saline conditions. Increase in salt levels had a negative and significant effect on seed yield, number of seeds per pod, number of pod per plant, pod length and plant height. The results showed that 45-min laser priming had the strongest effect on yield and yield components and reduced significantly the adverse effects of salinity. By contrast, laser radiation applied for 60 and 75 min, resulted in a dramatic decrease in yield and its components. Correlation coefficients between the attributes showed that canola yield had a positive and significant correlation with plant height, number of seeds, pod per main branch and lateral branches, length of pod and number of lateral branches. Effects of laser and salinity were significant on lateral branch pod length but not on main branch pods.K e y w o r d s: canola, laser irradiation, salt stress, yield, yield components INTRODUCTIONSalinity is known to adversely affect productivity of most crops worldwide (Ashraf, 2009) because their biomass and seed yield are significantly suppressed by this abiotic stress (Munns and Tester, 2008). Globally, more than 770 000 km 2 of lands are salt-affected by secondary salinization: 20% of irrigated land and about 2% of dry land agricultural land (Yildirim et al., 2006). In Asia, after pervious USSR, China, India and Pakistan the largest amount of saline soils belong to Iran (Szabolc, 1989). Canola represents its highest yield in proper and desirable soil conditions. However its growth, yield and oil yield can be reduced significantly by environmental stresses such as drought, salinity, water logging etc. Therefore, canola yield may reduce under saline soils (Ashraf and Mc Neilly, 2004).Among the various methods of priming it seems that there is little information about physical methods. But in recent years, interest in the use of physical methods of plant growing stimulation has increased (Carbonell et al., 2000;Dinoev, 2006;Hernandez et al., 2010; Vasilevski, 2003). Also in recent years the use of laser radiation in biology and agriculture extended widely and rapidly. Hernandez et al. (2006) reported that laser radiation increased the emergence speed and percentage, dry mass of seedlings and, ultimately, significantly increased the yield of laser radiated seeds. In the case of physical treatment the energy introduced in the cell creates conditions for molecular transformations and, as a result, the necessary substances are provided for the cell (Aladjadjiyan, 2007).The purpose of this experiment was to study different laser intensities for priming canola seeds as well as to measure how different densities of laser radiation affect canola yield and performance under salt stress conditions. MATERIALS AND METHODSThe experiment was conducted as factorial in the compl...

Drought and salinity stress management for higher and sustainable canola (Brassica napus L.) production: a critical review

“…Reduced plant height caused by saline stress is caused by reduced osmotic and leaf water potential, and increased electrolyte leakage (Dolatabadi and Toorchi, 2017). Salt stress negatively impacted canola seed germination (Mahmoodzadeh, 2008), radicle and plumule length and seedling fresh weight (Bybordi and Tabatabaei, 2009;Bybordi, 2010a), reduced biomass (Bybordi, 2010b), inhibited the seed-filling phase, reduced the number of seeds per pod, number of pods per plant, pod length and plant height (Zamani et al, 2010;Mohammadi et al, 2012), formed fewer leaves, branches, flowers, siliques, shorter siliques, and fewer seed per silique and 1000-seed weight (Mahmoodzadeh, 2008), reduced leaf size and nutrient absorption levels of leaves (Shainberg and Shalhevet, 2012), reduced root, hypocotyl and leaf growth in seedlings with a concomitant rise in IAA oxidase and peroxidase activity (Bybordi et al, 2010a), reduced chl a, chl b and total chl content (Nazarbeygi et al, 2011;Bahrani, 2013), reduced total fatty acids by 25% (Bybordi et al, 2010b), reduced dry matter, plant height, seed yield and 1000-seed weight (Shabani et al, 2013), and reduced root length, seedling fresh weight, seedling dry weight, RWC, ion leakage and chl content in seedlings of five cowpea cultivars (El-Shaieny, 2015). The decrease in chl content as salinity increased resulted in lower dry weight and reduced leaf area, but this reduction in leaf area and plant height did not occur in salt-resistant canola cultivars (Kamrani et al, 2013).…”

Electromagnetic field in corn grain production and health

“…San Juan hybrid presented its maximum yield with an exposure time of 6 min (plus 6.52%), equivalent to an increment of 600 kg ha -1 of grain. Hybrid response to electromagnetic irradiation was similar to the one observed in maize seedlings by Hernández et al (2009); there is, however, little information about the effect of electromagnetic field on maize growth and production; in crops like canola, an increase of seed yield per pod was observed (Mohammadi et al, 2012) and higher yield in wheat, 12.5 and 14.5% (Pietruszewski and Kania, 2010).…”

“…In mushrooms under the same conditions, fresh weight and dry matter increased by 76.42 and 38.26%, and the days to head appearance were reduced by 26.86% ; in pea, length and dry weight of seedlings increased by 140.5 and 91.3% . Mohammadi et al (2012) observed that canola seed exposed to laser radiation during 45 min showed significant effect on seed yield per pod and reduction of the impact of salt stress in soil. Higher accumulation of dry matter and sugar content, compared to the non-irradiated plants was observed, when radiating sugar beet seed with laser at pre-sowing (Sacala et al, 2012).…”

Thermal Effects of Laser Irradiation on Maize Seeds

“…The variations of temperature will be a function of the seed characteristics, as well as the exposure time to the laser beam (Hernandez et al, 2010). The exposure times to red laser irradiation (wavelength from 618 to 780 nm) have ranged from milliseconds, seconds, minutes to hours using several lasers (Aladjadjiyan, 2012;Hoseini et al, 2013;Khalifa and Ghandoor, 2011;Metwally et al, 2013;Mohammadi et al, 2012;Podleśny et al, 2012). Therefore, the objective of the present study was to determine the evolution of the temperature in maize seeds (Zea mays L.) when LILI was applied during 60 s and after 60 s of laser off, evaluating the temperature variation by using a thermal camera.…”