Journal of Plant Physiology and Breeding
Volume:11 Issue: 2, Summer-Autumn 2021

The application of sulfur as a pesticide is a strategy in plant protection, but in addition to their many benefits for pest control, pesticides may affect crop characteristics. In this study, movento (0.5 L/1000 L), confidor (0.4 L/1000 L), and refinery micronized (R) and mineral (M) sulfur (30 and 60 kg/1000 L in water) were sprayed on pistachio trees of the cultivar ‘Ahmadaghaei’ twice (in middle May and after 50 days) for controlling the psylla. Pistachios were harvested in late September and stored at 4 °C for 25 and 50 days. The effect of pesticides on hulls and kernels was then evaluated. Weight of pistachios, phenolic content of kernel, and chlorophyll and carotenoid contents of hull and kernel declined over time, while phenolic content of hull displayed an increasing trend. DPPH scavenging capacity of hull and kernel remained stable over time. Refinery micronized sulfur at both concentrations caused a higher weight loss on day 25 but it was similar to control after 50 days. It caused higher chlorophyll and lower carotenoid of hull and kernel. Mineral sulfur at both concentrations caused higher chlorophyll content of hulls. All sulfur treatments reduced the antioxidant activity of the hull and kernel, while elevating the hull phenolic content. Movento and Confidor pesticides stimulated loss of weight. Although the chemical pesticides and sulfur cannot easily penetrate the kernel, the physiological status of the hull and the whole plant may influence the kernels and the yield.

A two-year experiment was performed to evaluate the efficacies of nano-superabsorbent and bio-fertilizers on the field performance of rapeseed under different levels of irrigation in 2018 and 2019. The experiment was arranged as the split-plot factorial based on a randomized complete block design with three replications. Three irrigation levels (I1, I2, I3: irrigation after 70, 120, and 170 mm evaporation from class A pan, respectively) were arranged in main plots and factorial combination of two levels of nano-superabsorbent (0 and 45 kg ha-1) and four levels of bio-fertilizers (control, Azotobacter and Enterobacter, chitosan, and bacteria + chitosan) in sub-plots. The activities of antioxidant enzymes, hydrogen peroxide, osmolytes, and malondialdehyde content were increased under I2 and I3. This reaction led to a decline in leaf water content, membrane stability index, leaf protein content, and yield-related traits. Application of bio-fertilizers especially chitosan + plant growth-promoting bacteria (PGPR) with and without nano-superabsorbent increased antioxidant enzymes activities. Utilization of nano-superabsorbent decreased the activity of these enzymes. The lack of reduction in these traits by application of nano-superabsorbent + bio-fertilizers indicates that the additive effect of chitosan + bacteria is more than the reduction effect of nano-superabsorbent on these enzymes' activity. The utilization of nano-superabsorbent with bio-fertilizers increased these enzymes’ activities through higher nitrogen retention in the soil and increased fertilizer effect. The utilization of chitosan, PGPR, and nano-superabsorbent, especially chitosan + PGPR + nano-superabsorbent, decreased proline content, however, increased soluble sugars, protein, chlorophyll, leaf water contents, and membrane stability index, and consequently, these treatments affected yield-related traits of rapeseed under water stress conditions.

To investigate the effect of drought stress on the physiological and chemical properties of the sweet pepper and the impact of the foliar application of salicylic acid (SA) on alleviating the negative effects of this stress, a factorial experiment was carried out using a completely randomized design in the greenhouse conditions. Drought stress levels were 100% field capacity (as control), moderate stress (60% field capacity), and severe stress (30% field capacity). Foliar SA was also applied at three concentrations of 0 (as control), 0.5, and 1 mM when the plants were at the four-leaf stage. The results showed that drought reduced shoot and root fresh weight and dry weight, relative leaf water content, fruit length and diameter, chlorophyll index, and leaf area, and increased electrical conductivity, antioxidant capacity, total phenolic content, ascorbate, polyphenol oxidase, and ascorbate peroxidase. After foliar of application SA, electrical conductivity decreased and other above-mentioned characteristics increased, however, the increase in shoot dry weight, root fresh weight, and chlorophyll index was not significant. From the results of this experiment, it can be concluded that SA alleviates the negative effects of drought stress in pepper.

77Germinated grains are a rich source of minerals, water-soluble vitamins, enzymes, and soluble sugars that can be applied by foliar spraying on the foliage of crop plants where photosynthesis takes place. A field experiment was conducted during the rice-growing season of 2020 to evaluate the effect of grass pea sprout extract on the growth and yield of two common local varieties of rice (Anbarbou and Shamshiri). The experiment was the 2 × 2 factorial combination of grass pea extract spray (2%) and rice cultivar. (based on the randomized complete block design with three replicates. Irrespective of foliar spray with grass pea extract, a significant difference between the two cultivars was observed for seed phosphorus and zinc content, and phytic acid concentration. Plants sprayed with the grass pea sprout extract significantly displayed greater net photosynthesis and water use efficiency. Grain yield, panicle number, grain number, grain weight, fresh and dry matter accumulations, and panicle length of plants at harvest increased up to 7.4%, 23.91%, 7.39%, 4.44%, 18.49%, 16.85%, and 26.5%, respectively, due to foliar application with the grass pea extract. Grain P content sprayed with the grass pea extract increased up to 65.38%, irrespective of the type of cultivar. Also, foliar spraying improved grain Zn content from 10.54 µg g-1 to 29.75 µg g-1. Although, the grain phytic acid increased from 4.86 mg g-1 to 6.71 mg g-1 by foliar spraying of the grass pea sprout extract, however, the ratio of phytic acid to Zn content in the grain decreased from 46.11 to 22.55%. Foliar spraying increased grain Zn content in Anbarbou by 1.2-fold as compared to Shamshiri. On the other hand, foliar spraying increased grain phytic acid concentration in Shamshiri by 1.65-fold as compared to Anbarbou. It seems that spraying the rice plants with the grass pea sprout extract was beneficial in terms of agronomic and physiologic characteristics and nutrients such as Zn and P. Also, Anbarbou responded better to the sprout extract than the Shamshiri cultivar.

Lentil is one of the arctic legumes which can be damaged by the severe cold. In this regard, determination of the cold tolerance among different lentil lines or varieties has considerable importance. To evaluate Bilesovar and Precoz varieties and ILL-2580 line of lentils for cold tolerance and seed yield, a field experiment was carried out as a randomized complete block design with three replications. Also, to study the physiological and biochemical responses of the lentil plants to cold conditions, a factorial experiment was conducted in the greenhouse based on a completely randomized design. The factors were cold conditions and lentil genotypes. The results showed that the highest plant height, 100-seed weight, seed yield, and the shoot dry and fresh weight were observed in the Bilesovar variety followed by Precoz. Also, the highest percentage of cold damage was observed in the ILL-2580 line. The cold damage was 80% in ILL-2580 but it was about 41 and 32% for the Bilesovar and Precoz, respectively. The results also indicated that the chlorophyll index (SPAD) declined in Billesovar and ILL-2580 under the cold stress conditions, whereas it enhanced in Precoz (252% over the control). Moreover, the proline content was significantly increased by about 300% in the cold-treated Percoz plants as compared to the control plants. The activity of the catalase, as an antioxidant enzyme, drastically increased in Precoz and Bilesavar under cold treatment (20 and 73%, respectively over the related controls). Billesovar showed a significant increase in total flavonoids and anthocyanin content of the leaves at cold conditions. The results of SDS PAGE analysis showed that in Bilesavar and Precoz, some characteristic bands with molecular weights of 30-40 and 80-90 KD appeared in the cold-treated plants that were absent in the control plants. It can be concluded that the Bilesovar of lentils might be considered a cold-tolerant variety. On the other hand, Precoz and ILL-2580 can be regarded as semi-tolerant and cold-sensitive genotypes, respectively.

The objective of the present study was to estimate the genetic parameters and hybrid vigor of yield and yield contributing traits in lentil through additive-dominance model. Mean  found to be significant in all cases which indicating polygenic nature of the traits. Parameters [d] and [h] significant in few cases indicating that both additive and dominant gene effects played an important role in the inheritance of the respective traits. In all crosses and for all characters, mid-parent and high-parent heterosis were not significant except the cross P5 × P6. Potence was non-significant in most cases which indicated that differences don’t exist between F1 and F2 generations. It was revealed from the joint scaling test that for most characters in different crosses χ2 values were not significant. Non-significant χ2 test indicated the adequacy of additive-dominance model and hence those traits carry only additive and dominant genes which can be used in breeding programs to improve lentil varieties.

To identify the most effective characteristics on grain yield, 24 super-sweet maize inbred lines were investigated under two moisture conditions (normal and drought stress) during the 2017 growing season. The experiment was carried out as a randomized complete block design with four replications. Analysis of variance for grain yield and eight agronomic characteristics showed significant differences among investigated inbred lines. Phenotypic correlations indicated that grain yield had a significant relationship with kernel number per row, ear diameter, row number per ear, and stem diameter under normal conditions, and with kernel number per row and plant height under drought-stress conditions. Stepwise multiple linear regression showed that kernel number per row, ear diameter, and stem diameter explained 72% of the variation for grain yield at normal conditions. On the other hand, cob present, plant height, ear diameter, and ear length governed 60% of the grain yield variation under drought-stress conditions. Path analysis under normal conditions revealed that kernel number per row had the highest positive direct effect (0.717) on the grain yield followed by the stem diameter (0.292) and ear diameter (0.273). In the drought stress conditions, ear diameter (0.455) and plant height (0.436) showed the highest positive direct effects on grain yield.

Rosa damascena is an important commercial crop in ornamental horticulture. Also, its essential oils and phenolic compounds are used in the medicinal, food, flavor, and perfume industries. The shoot and root regeneration of axillary single-node explants was studied on 16 and 24 different media, respectively. The combinations of 1, 1.5, 2, and 2.5 mg-1 of 6-benzylaminopurine (BAP) with 0.1 and 0.05 mgl-1 auxins [(2,4-D and 1-naphthaleneacetic acid (NAA)] and 0.1 mgl-1 gibberellic acid (GA3) were investigated for shoot induction. Shoot induction and proliferation were observed 16 and 38 days after planting, respectively. The highest shoot proliferation (100%) was obtained in the presence of 2.5 mgl-1 BAP and 0.05 mgl-1 of 2,4-D (medium 16). Root formation and growth of healthy shoots were studied on various combinations of indole-3 acetic acid (IAA) (0, 0.05, and 0.1 mgl-1) with full-strength and half-strength MS media in the solid and liquid culture media (12 media). In the optimal medium, root initiation and growth occurred 125 and 138 days after culturing, respectively. The successful rooting process occurred just in two media with rooting frequency of 31 and 53% respectively. Rooting frequency was higher in the half-strength MS liquid media than in the other media.

The current research was performed to evaluate 150 barley cultivars based on several agronomic and physiological traits. The experiment was conducted as an alpha lattice design with five incomplete blocks in two replications at normal and salinity stress (EC= 12 dsm-1) conditions at Agriculture and Natural Resources Research and Education Center, Yazd, Iran, for two years. The combined analysis of variance showed a significant difference among genotypes in all traits except harvest index and relative water content, indicating the existence of genetic diversity among the evaluated barley genotypes. Phenotypic correlation coefficients based on the average of two cropping years showed that biological yield, days to physiological maturity, and leaf chlorophyll index under normal conditions and biological yield, harvest index, number of fertile tillers, and plant height under salinity stress had a significant positive correlation with grain yield. According to the path analysis, the days to physiological maturity and number of fertile tillers had the highest positive direct effect on grain yield in normal and salinity stress conditions, respectively, followed by leaf chlorophyll index in the normal conditions and plant height under salinity stress. Cluster analysis by Ward’s method grouped the studied genotypes into three clusters in both environments based on an average of two years. The discriminant function analysis was used to determine the number of clusters and check the accuracy of the grouping in the cluster analysis. Percentage deviation from the grand mean of clusters under salinity stress showed that genotypes of the first cluster had the highest grain yield and have the shortest maturity period. In the second cluster, physiologically efficient genotypes, and in the third cluster, late maturing and low-yielding genotypes were included. Therefore, according to the results of this study, it can be concluded that under salinity stress, the genotypes of the first cluster with the highest grain yield and earliest maturity dates can be used in future breeding programs to improve the salinity tolerance.

Climate change may contribute to drought stress and limit crop production. The oilseed rape (Brassica napus L.) cultivation area has declined due to drought stress. Identification of high-yielding and tolerant varieties could be regarded as a solution to this problem. Twelve oilseed rape genotypes were planted under drought stress and normal conditions in Lishtar, Gachsaran, Iran, using a randomized complete block design with three replications in 2017. A considerable decline in the pods per plant (76%), pod length (20%), grain yield (80%), biomass (73%), harvest index (37%), plant height (34%), seeds per pod (41%) and branches per plant (41%) of genotypes was observed in the evaluated genotypes of the oilseed rape as the consequence of drought stress. In general, grain yield, biomass, and pods per plant had a very high sensitivity to moisture reduction. The significant direct effect of the pod number and 1000-seed weight on the grain yield showed that these characteristics can be used to select the promising genotypes to increase the grain yield of oilseed rape under normal conditions. Under drought stress conditions, branch number per plant, pod length, and seeds per pod had a significant direct effect on grain yield. Increasing these traits and reducing the plant height and shortening the growth period may improve the grain yield of the oilseed rape. Hyola401, RGS003, and Hyola308, showed the highest grain yield under both drought stress and normal conditions among the evaluated oilseed rape genotypes. They may be regarded as the promising varieties to be planted in the conditions of the experimental site or similar areas.

Lilium spp. belong to the Liliaceae family. This plant contains a valuable secondary metabolite which can be increased by the stimuli treatment. The main goal of the present study was to evaluate the effects of chitosan as a stimulant on regeneration and production of secondary metabolites of Lilium regale. The experiment was carried out as a completely randomized design in the MS medium with 10 replications. Five different concentrations (0, 50, 100, 150, and 200 mg/L) of chitosan were used as treatments. Different morphological traits, leaf chlorophyll, and secondary metabolites were measured. Analysis of variance showed that chitosan significantly affected plant height, fresh weight, bulblet number, root number, chlorophyll a and b, total chlorophyll, phenols, flavonoids, and regeneration percentage. The highest and lowest fresh weight and root number were obtained from 200 ppm of chitosan and the control, respectively. The results also showed that the plant height and bulblet number in all concentrations of chitosan were higher than the control. The highest and lowest regeneration rate were obtained from the 200 ppm chitosan and the control, respectively. However, the highest amount of phenols, flavonoids, and chlorophyll was obtained from the 200 ppm chitosan. According to the results of the present study, chitosan at the rate of 200 ppm had a more positive effect on regeneration and production of secondary metabolites of Lilium regale compared to other concentrations.

Salinity is a big problem for agriculture and crop productivity worldwide. Barley is considered notably salt-tolerant and there is considerable genetic variation in barley in response to salinity. In the present study, the expression pattern of AOS, AOC, OMT, L1S1, and NHX1 genes were investigated in the roots of three barley genotypes, Sahara3771, Clipper, and an advanced breeding line (A-line) 24 hours, 3 days, and 3 weeks after 100 and 200 mM NaCl treatments as well as control (no NaCl). Analysis of variance revealed significant salinity x genotype x salt exposure time interaction for all the studied genes, except AOC. The highest expression level of the AOC gene was noted under 200 mM NaCl in Clipper and the lowest expression was recorded under 200 mM and 100 mM NaCl in A-line and Clipper, respectively. For the AOS gene, the highest expression level was recorded 3 weeks after 200 mM NaCl treatment. The maximum expression level of NHX1 was measured in A-Line 24 hours after 100 mM NaCl treatment and the lowest in Sahara3771 3 weeks after 200 mM NaCl treatment. The OMT gene showed the highest expression in Sahara3771 3 weeks after 100 mM NaCl treatment and the lowest was observed in A-Line under 200 and 100 mM NaCl. For the LlS1 gene, the highest level of the transcripts was measured 3 weeks after 100 mM NaCl treatment. LlS1 gene showed the lowest expression level 24 hours after 200 mM NaCl in Sahara3771.