Spikelets Research Articles

Analysis of the Morphological Diversity of Inflorescence of Six Tunisian Date Palm (Phoenix dactylifera L.) Pollinators

Six Tunisian date palm pollinators were morphologically characterized at the inflorescence level. The aim was to assess the level of similarity between the spathe of the three flowering stages. Nineteen qualitative and quantitative characteristics were explored and subjected to multivariate analyzes. The results showed that inflorescences morphological similarity oscillated between 97.9 and 62.2% with an average of 80.1%, which testifies strong genetic relations among the six genotypes and among flowering stages/cycles within each genotype. Principal Component Analysis (PCA) analysis shows that weight of the spathe (SW), number of spathe (NS), shape of spathe (SS), total length of the spathe (TLS), shape of spikelets (SPS), number of spikelets per spathe (NS), These characteristics are defined by axis 1 and 2 which absorbing a total of 56.3% of total variability. Phylogenetic relationship analysis showed that two groups were distinguished by a high level of genetic similarity of inflorescences at each flowering stage. According to the analysis, the second flowering stage is the most distinguished morphologically with the highest sizes of the quantitative characteristics studied.

Comparative transcriptomics provide new insights into the mechanisms by which foliar silicon alleviates the effects of cadmium exposure in rice

Silicon (Si) has been shown to alleviate Cd stress in rice. Here, we investigated the beneficial effects of foliar Si in an indica rice Huanghuazhan (HHZ). Our results showed that foliar Si increases the dry weight and decreases Cd translocation in Cd-exposed rice at the grain-filling stage only, implying that the filling stage is critical for foliar Si to reduce Cd accumulation. We also investigated the transcriptomics in flag leaves (FLs), spikelets (SPs), and node Is (NIs) of Cd-exposed HHZ after foliar Si application at the filling stage. Importantly, the gene expression profiles associated with the Si-mediated alleviation of Cd stress were tissue specific, while shared pathways were mediated by Si in Cd-exposed rice tissues. Furthermore, after the Si treatment of Cd-exposed rice, the ATP-binding cassette (ABC)-transporters were mostly upregulated in FL and SP, while the bivalent cation transporters were mostly downregulated in FL and NI, possibly helping to reduce Cd accumulation. The genes associated with essential nutrient transporters, carbohydrate and secondary metabolite biosynthesis, and cytochrome oxidase activity were mostly upregulated in Cd-exposed FL and SP, which may help to alleviate oxidative stress and improve plant growth under Cd exposure. Interestingly, genes responsible for signal transduction were negatively regulated in FL, but positively regulated in SP, by foliar Si. Our results provide transcriptomic evidence that foliar Si plays an active role in alleviating the effects of Cd exposure in rice. In particular, foliar Si may alter the expression pattern of genes associated with transport, biosynthesis and metabolism, and oxidation reduction.

Checking the Significance of Correlation Coefficient from the Regression Analysis using Wheat Yield.

Major objective of the present study is estimate regression model and Correlation coefficient. The data were collected from the wheat section, Agriculture Research Institute (ARI) Tandojam, regarding various factors influencing on the wheat production. The survey result show that yield has significant positive correlation with the parameters such as the number of tillers per plant, number of seed per spike, length of spike in cm, the number of spikes let per, tiller per hectare and plant height cm. The parameter of wheat number of tillers per plant meter square standard error is (0.569), coefficient is (0.816). T-value is (1.43) and with positively significant is (0.018). The parameter of number of seed per spike standard error is (0.107) coefficient is (0.0811) To determine the effect of dependent and independent T-value of (0.75) with significant (0.4724).The parameter of wheat is length of spike in cm is standard error is (1.704), Coefficient is (1.092), T-value is (0.64) with the positively significant is (0.029) T-value is (2.20) and with positively significant is (0.039).The parameter of tiller per hectare is standard error is (0.026), standardized The Number of spike let per spike with standard error of this parameter (0.5172)coefficient is (1.135), the coefficients beta is (0.041), and T-value of this parameter is (1.73) and with the positively significant value is (0.121). The parameter of wheat is day of heading cm with the standard error is (0.650), the standardized coefficient beta is negative (1.426), the T – value of this parameter is (-2.19) with the weak significant of (0.059). The parameter of wheat is plant height cm standard error is (0.203), with standardized coefficient beta is (0.081), T-value of this parameter is (0.40) with the significant value is (0.697). The parameter of lodging score per hector centimeter with standard error is (0.662), the standard coefficient of beta is (-0.504), T-value of this parameter is (-0.76), with the significant of (0.468).The parameter of number of grains weight in grams with standard error is (0.245) standardized coefficient of beta is (0.106), T-value is (0.43) with the significant value is (0.677). The parameter of wheat is seed index 1000 grains weight with standard error is (3.437) , coefficient is (0.384) , T-value is (0.11) With the significant value is (0.913).The parameter of wheat is plot yield gram with standard error is (0.0215), with coefficients is (-0.036), is T-value of this parameter is (-1.72) with the significant value is (0.124). The Parameter of wheat is nitrogen per hector kilogram with standard error is (0.168), coefficient is (0.1688), is T-value is (1.00) with the significant of (0.345).The parameter of Phosphorus per hack Kg with standard error is (0.333), coefficient of is (-0.138), T-value is this parameter is (-0.42) with the significant of (0.688). It is suggested that the more factors can be studied and different statistical techniques, agronomics practices and different doses of fertilizer can be applied for the high production of wheat crop.

Evaluation of wheat genotypes (Triticum aestivum L.) for yield and yield characteristics under low land area at Arba Minch, Southern Ethiopia

The objective of this research was to evaluate wheat genotypes for yield and yield characteristics under the low land area of Arba Minch, Southern Ethiopia. A field experiment was conducted with 27 bread wheat genotypes in a randomized complete block design with two replications at Amibara Farm, Arba Minch from March to June 2020. Varieties differed significantly (p<0.01) for the yield related characters and yield. The major findings include identification of varieties with earliest heading and physiological maturity, highest number of effective tillers formed, ear length and spikelets in the ear, grains in ear and spikelet, thousand grains weight, and grain yield. It could be concluded that varieties, Lucy, Fentale-1, Amibara-2, Alidoro, Ogolcha, Daka, Fentale-2, Ga’ambo, Amibara-1 and Werer-2 were high yielding under lowland area at Arba Minch. It is recommended that these varieties should be further tested for identification and selection of high yielding ones for lowland areas in Southern Ethiopia. Key words: Bread wheat, varieties, yield characteristics, grain yield, lowland, Ethiopia.

The Role of Rice Vacuolar Invertase2 in Seed Size Control.

Sink strength optimizes sucrose import, which is fundamental to support developing seed grains and increase crop yields, including those of rice (Oryza sativa). In this regard, little is known about the function of vacuolar invertase (VIN) in controlling sink strength and thereby seed size. Here, in rice we analyzed mutants of two VINs, OsVIN1 and OsVIN2, to examine their role during seed development. In a phenotypic analysis of the T-DNA insertion mutants, only the OsVIN2 mutant osvin2-1 exhibited reduced seed size and grain weight. Scanning electron microscopy analysis revealed that the small seed grains of osvin2-1 can be attributed to a reduction in spikelet size. A significant decrease in VIN activity and hexose level in the osvin2-1 spikelets interfered with spikelet growth. In addition, significant reduction in starch and increase in sucrose, which are characteristic features of reduced turnover and flux of sucrose due to impaired sink strength, were evident in the pre-storage stage of osvin2-1 developing grains. In situ hybridization analysis found that expression of OsVIN2 was predominant in the endocarp of developing grains. A genetically complemented line with a native genomic clone of OsVIN2 rescued reduced VIN activity and seed size. Two additional mutants, osvin2-2 and osvin2-3 generated by the CRISPR/Cas9 method, exhibited phenotypes similar to those of osvin2-1 in spikelet and seed size, VIN activity, and sugar metabolites. These results clearly demonstrate an important role of OsVIN2 as sink strength modulator that is critical for the maintenance of sucrose flux into developing seed grains.

Overexpression of RICE FLOWERING LOCUS T 1 (RFT1) Induces Extremely Early Flowering in Rice.

RICE FLOWERING LOCUS T 1 (RFT1) is a major florigen that functions to induce reproductive development in the shoot apical meristem (SAM). To further our study of RFT1, we overexpressed the gene and examined the expression patterns of major regulatory genes during floral transition and inflorescence development. Overexpression induced extremely early flowering in the transgenics, and a majority of those calli directly formed spikelets with a few spikelets, thus bypassing normal vegetative development. FRUITFULL (FUL)-clade genes OsMADS14, OsMADS15, and OsMADS18 were highly induced in the RFT1-expressing meristems. OsMADS34 was also induced in the meristems. This indicated that RFT1 promotes the expression of major regulatory genes that are important for inflorescence development. RFT1 overexpression also induced SEPALLATA (SEP)-clade genes OsMADS1, OsMADS5, and OsMADS7 in the greening calli before floral transition occurred. This suggested their possible roles at the early reproductive stages. We found it interesting that expression of OsFD1 as well as OsFD2 and OsFD3 was strongly increased in the RFT1-expressing calli and spikelets. At a low frequency, those calli produced plants with a few leaves that generated a panicle with a small number of spikelets. In the transgenic leaves, the FUL-clade genes and OsMADS34 were induced, but SEP-clade gene expression was not increased. This indicated that OsMADS14, OsMADS15, OsMADS18, and OsMADS34 act immediately downstream of RFT1.

Heterosis studies for yield and agronomic traits in Thai upland rice

The exploitation of heterosis and heterobeltiosis are the promising way for raising yield potential in crops. Twenty-eight F1 hybrids and their eight parents were evaluated to estimate the heterosis and heterobeltiosis of yield and other agronomic traits in Thai upland rice. Significant differences of analysis of variance were observed for all studied traits, indicating the existence of worth genetic variability among the hybrids and their parents. The highest significant positive heterosis and heterobeltiosis was attained by Dawk Pa-yawm × Hawm Mali Doi for number of tillers (90.59%; 58.82%) and number of panicles plant-1 (60.35%; 46.14%), and panicle length (heterobeltiosis: 20.05%), but highest significant negative heterosis for plant height (-8.90%). Likewise, Nual Hawm × Khun Nan showed the highest significant positive heterosis and heterobeltiosis for yield components, viz., number of filled grains panicle-1 (57.39%; 52.25%), spikelet fertility (25.01%; 21.16%), 1000 grain weight (heterosis: 12.85%) and grain yield plant-1 (heterosis: 19.86%), but highest significant negative for days to flowering (-17.52%; -6.03%) and days to maturity (-12.00%; -4.91%). These crosses were recommended as the most promising combinations to gain early favorable segregants and developing high yielding upland rice hybrid varieties by heterosis breeding.

Histone Deacetylase 701 (HDT701) Induces Flowering in Rice by Modulating Expression of OsIDS1.

Rice is a facultative short-day (SD) plant in which flowering is induced under SD conditions or by other environmental factors and internal genetic programs. Overexpression of Histone Deacetylase 701 (HDT701) accelerates flowering in hybrid rice. In this study, mutants defective in HDT701 flowered late under both SD and long-day conditions. Expression levels of florigens Heading date 3a (Hd3a) and Rice Flowering Locus T1 (RFT1), and their immediate upstream floral activator Early heading date 1 (Ehd1), were significantly decreased in the hdt701 mutants, indicating that HDT701 functions upstream of Ehd1 in controlling flowering time. Transcript levels of OsINDETERMINATE SPIKELET 1 (OsIDS1), an upstream repressor of Ehd1, were significantly increased in the mutants while those of OsGI and Hd1 were reduced. Chromatin-immunoprecipitation assays revealed that HDT701 directly binds to the promoter region of OsIDS1. These results suggest that HDT701 induces flowering by suppressing OsIDS1.

Effects of zeolite application on grain yield, water use and nitrogen uptake of rice under alternate wetting and drying irrigation

With the increasing scarcity of water resources and growing population, the dual goal of saving irrigation water and increasing grain yield has become a major challenge in rice production around the world. A two-year lysimetric experiment was conducted to assess the effects of zeolite application (Z0: 0 and Z1: 15 t/hm2) and water regimes (W0: continuous flooding irrigation, W1: energy-controlled irrigation, W2: alternate wetting and drying irrigation) on grain yield, water use and total nitrogen uptake of rice. Zeolite addition to paddy field significantly increased grain yield, total N uptake, and water use efficiency (WUE), despite a negligible effect on amount of irrigation water used. Compared with W0, the separate use of W1 and W2 each considerably decreased irrigation water. However, W2-grown rice showed a significant decline in grain yield. In contrast, W1 showed comparable grain yield with W0, and achieved the highest WUE. Correlation analysis revealed that grain yield was significantly and positively correlated with effective panicles, spikelets per panicle, water consumption, and total N uptake. It is concluded that the combination of zeolite application at the rate of 15 t/hm2 and energy-controlled irrigation could be recommended to benefit farmers by reducing irrigation water while improving grain yield on a clay loam soil. Keywords: zeolite, alternate wetting and drying irrigation, rice, yield, water use efficiency DOI: 10.25165/j.ijabe.20181101.3064 Citation: Zheng J L, Chen T T, Xia G M, Chen W, Liu G Y, Chi D C. Effects of zeolite application on grain yield, water use and nitrogen uptake of rice under alternate wetting and drying irrigation. Int J Agric & Biol Eng, 2018; 11(1): 157–164.

Inheritance studies of aroma and yield attributes in rice (Oryza sativa L.) genotypes

Low yield is one of the main challenges of rice production in Ghana due to poor production practice, environmental stresses and plant genotype. The choice of an efficient breeding procedure depends to a large extent on knowledge of the genetic system controlling the character to be selected. This experiment was done to study the inheritance pattern of aroma attribute of rice and estimate the heritability for some yield attributes in rice (Oryza sativa L.). Six generations viz., P1, P2, F1, F2, BCP1 and BCP2 of a cross between IET6279 and IR70445-146-3-3 were used for the study. A randomized complete block design (RCBD) was used with three replications. All the F1 and BCP1 plants of the cross were non-aromatic indicting that the gene controlling aroma in the donor parent was recessive. The segregation ratio of aromatic to non-aromatic plants was 1:3 in F2 and 1:1 in BCP2 plants, confirming the monogenic inheritance of aroma. This shows that there would be a high probability of success in selecting for aroma using pedigree breeding in early generations of F2. High broad sense heritability estimates were observed for all the characters studied except for number of fertile spikelets per plant, suggesting that the influence of the environment was minimal for these characters. Hence, these traits would respond to selection owing to their high genetic variability and transmissibility. Thus, selection based on phenotypic value of these characters would be reliable and effective with low broad sense heritability for number of fertile spikelets per plant, indicating that influence of the environment was high for these characters. Therefore, superior genotypes selection based on phenotypic performance for this trait may not be effective. The analysis of gene effects revealed that additive, dominance and epistatic effects were involved in the inheritance of all the traits studied. However, additive effect, in general was higher in magnitude than dominance gene effect in all the characters. All the traits manifested non-allelic interactions, indicating that epistasis is determined to some extent by the genotypes used for the study. Thus, in the presence of epistasis, grain width showed significant duplicate type of gene interaction which restricted the scope of simple selection for the characters studied. Therefore delaying selections to later generations using recurrent selection will enhance success in improving yield attributes in all genotypes studied. Key words: Aroma, inheritance, additive, gene action, heritability, monogenic, non-additive, recessive.

VERTICAL DISTRIBUTIONS OF FUSARIUM spp. INFECTIONS ON MATURE WHEAT EARS UNDER NATURAL FIELD CONDITIONS

Wheat spikes have a vertical architecture, presenting multiple spikelets on which Fusarium spp. infectious propagules can land, initiate grain infection and possibly spread into the rachis to infect neighboring kernels. However, it is not known whether fungal infections occur randomly along the ear nor if species naturally interact within the ear. Over 4 years, five wheat fields in Belgium were surveyed annually and Fusarium spp. were isolated from kernels sampled from three positions on the ears (top, middle and bottom). This study revealed a vertical gradient of infection by Fusarium spp., with more isolates recovered from the bottom than from the top of the ears. This observation could result from infections by an inoculum from the ground, a downward movement of propagules present on the ear surface carried by rain and/or a downward spread of the fungus within the rachis. Moreover, multiple infected kernels originating from the same spike were frequent but, in most cases, the same species could be isolated from those grains and almost no relationships were observed among species present on the same spikes. Therefore, Fusarium spp. infections on wheat ears occur preferentially at the bottom of the spike and independently of the other species present.

Genetic effects on panicle traits of crossbred rainfed rice cultivars using generation mean analysis

The nature and magnitude of gene effects involved in expression of panicle traits in rainfed rice cultivars were estimated among a wide range of crosses using generation mean analysis. The parental lines comprised of two low-land and six upland rain-fed rice. The lowland parents were used as pollen parents and the upland genotypes were maintained as the seed parents. Crosses were made between them to obtain the F1 hybrids. Backcrosses were produced by crossing the F1 hybrids to their pollen parent to obtain BC1.1 and seed parents to produce BC1.2. The result revealed significant differences (P ≤ 0.05) among the genotypes for all the characters studied. Except for Max x CT7127-49 where P2 and F2 plants of WITA 4 x NERICA 1 that produced long panicles (29.28 and 26.13 cm) that differed significantly (P ≤ 0.05) from other generations, F1 plants produced the longest panicles in the other crosses followed by the F2 plants. For most traits, F1 generation means were higher than the mid-parent values. Significant differences observed between the F1 and F2 generation means in majority of the cases for percentage fertile spikelet and spikelet number per panicle is thought to be due to the diversity in these traits among the parental lines. The means of BC₁ and BC2 tended to be located close to those of their respective recurrent parents. Digenic epistatic model was adequate to explain variation in generation means for all the panicle traits for the pooled analysis. Most of the crosses manifested non-allelic interactions for number of spikelet per panicles and fertile spikelet per panicle and is an indication that epistasis is determined to some extent by the genotypes used for the study. Key words: Generation mean, dominance, additive, epistasis, F1, F2, parental line and backcross.

Combined use of Azolla and loach suppressed paddy weeds and increased organic rice yield: second season results

Organic farming uses alternatives to agricultural chemicals such as synthetic fertilizers and pesticides. The primary challenge in organic rice farming is controlling weeds without using herbicides and improving rice yield without chemical fertilizers. In our previous paper entitled as combined use of Azolla and loach suppressed weed Monochoria vaginalis and increased rice yield without agrochemicals, we reported the first year rice growth season results from an in situ container experiment. The experiment was designed with 4 treatments—control (with neither Azoll a nor loach), Azolla (Azolla alone), loach (loach alone), and Az+Lo (combined Azolla and loach)—with 3 replications each. The first year results showed that combined use of Azolla and loach was successful in weed suppression and increase in rice yield in 2012. In this paper, we report the second year results from the continuous container experiment in 2013. M.vaginalis emergences were very low in second year rice growth season on all treatments. Compared first year, the rice yields decreased in second year on all treatments due to different weather condition and with or without organic soybean oil cake application between two rice growth seasons. The second year results also showed the raising loach had a stronger effect to increase tiller and panicle numbers, and spikelet number per panicle, then improve rice yields to 2.3 times than control. The Azolla residues left from first year have weaker effect on rice growth and yield, but increase soil organic matter accumulation at second year. The two years study indicated that combined use of Azolla and loach can meet two of the greatest challenges in organic rice production: providing effective weed control and improving rice nutrition without agrochemicals.

Ekmeklik Buğday (Triticum aestivum L.)’da Tane Verimi ile Bazı Verim

This study was carried out to determine the direct and indirect effects of some yield components, such as plant height (PH), spike lenght (SL), spikelet number per spike (SNS), grain number per spike (GNS), grain weight per spike (GWS) and 1000 grains weight (1000GW), to grain yield using randomized complete block design with 3 replications in 22 advanced bread wheat line and 3 wheat varities (Flamura, Gonen, Pehlivan) at Application and Research Center, Uludag University Faculty of Agriculture, in years of 2009/10, 2010/11, 2011/12 and evaluated the relationship between agricultural traits by path analysis and correlation coefficient; was conluded that GNS and GWS can be used successfully for selection for grain yield at breeding wheat studies for Bursa conditions

The evaluation of adaptation of Eragrostis minor Host. (Poaceae) coenopopulations to the conditions of transformed environment.

Structural and functional features of E. minor, using morphometric traits and phytomass fractions of model coenopopulations are studied to determine adaptive capacity of species in different environments transformed the environment of forest, forest-steppe and steppe zones. Depending on edaphic conditions plants and organs of plants may increase several times in size and weight. The index of morphological integration of model coenopopulations indicates the uniformity of vegetative and generative organs of plants at different environmental conditions. In various conditions significant value to coenopopulations differentiation contribute signs of individual length as well as length and number of generative organs. Formation of the maximum number of spikelets (feature with the highest contribute to dispersion of data) corresponds to extreme edaphic conditions of growth combined with a high degree of recreation. However, decreasing environmental transformation is accompanied by double fulfillment of breeding potential of E. minor coenopopulations, while setting density of individuals reduce in almost 5-15 times. Thus, E. minor has mixed competitive Stress-tolerant Ruderal type as adaptation to condition of secondary areal.

A Peculiar Amphitropical Genus of Paniceae (Poaceae, Panicoideae)

Fil: Scataglini, Maria Amalia. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Instituto de Botanica Darwinion. Academia Nacional de Ciencias Exactas, Fisicas y Naturales. Instituto de Botanica Darwinion; Argentina

MARKER-ASSISTED SELECTION: EVALUATION OF BACTERIAL BLIGHT RESISTANCE IN THE PYRAMIDS OF FERTILITY RESTORER LINES

PRR78 and KMR3 are popular restorer lines of the rice (Oryza sativa L.) hybrids Pusa RH10 and KRH2, respectively. These lines are highly susceptible to bacterial leaf blight caused by Xanthomonas oryzae pv. oryzae. Nine families each of PRR78 and KMR3 pyramids containing Xa4, xa5, xa13 and Xa21 resistance genes were evaluated for agronomic and related characters (viz., days to 50% flowering, plant height, number of tillers, panicle length, filled grains per panicle, percentage of spikelet fertility, 1000 grain weight, yield, biomass, harvest index and disease resistance). There were no significant differences within the families of the pyramids with respect to any of the characters evaluated. Under disease-free conditions, there was no difference between the parents and the pyramid families for the characters evaluated. However, under inoculated conditions of heavy disease pressure: (i) the parents exhibited highly susceptible reaction, whereas all the families of pyramids of both genotypes were highly resistant; (ii) pronounced variation was observed between the parents and the pyramids under inoculated conditions for the characters viz., FG/P, SF %, 1000 GW and Y. With respect to yield under diseased conditions there was a loss to the extent of 28% in PRR78 and 24% in KMR3 compared to the pyramid families. The pyramids thus protected against the yield loss and pyramiding of the four resistance genes did not have any yield penalty. These pyramids can be used directly in the breeding programs or as potential donors of bacterial blight resistance.

Biosystematic Relationships among Three Sects’ Plants in Elymus(Poaceae) Based on the External Morphological Characteristics

The external morphology of the major species of sects.Elymus,Turczaninovia and Macrolepis in Elymus was analyzed,the similarities and the differences of the external morphological characteristics were summarized,and the taxonomic significance of external morphological features among them was discussed.Furthermore,according to the evolutionary trends of external morphological characters including inflorescences,spikelets,florets and paleas of three sects,their evolutionary positions and relationships were analyzed.The results show that the sect.Elymus is most primitive among three sects,the sect.Turczaninovia is advanced than the sect.Elymus,and the sect.Macrolepis is the most advanced sect.The sect.Elymus probably generated the sect.Turczaninovia,whereas the sect.Macrolepis was probably derived from the sect.Turczaninovia.The biosystematic relationships of tested species in Elymus were also discussed.The research provides the theoretic foundation for further studying the systematics and evolution of Elymus.

Physiological characterization of rice under salinity stress during vegetative and reproductive stages

Salinity is one of the major environmental factors limiting crop productivity. For this reason, a greenhouse experiment was conducted in Rasht, North of Iran during 2010 growing season to evaluate the salinity levels of irrigation water at different growth stages on the some physiological characterization of rice. Treatments were arranged in a randomized complete block design with two factors and three replications. Factor one included four levels of saline water (2, 4, 6, and 8 dS m -1 ); factor two consisted of four growth stages (tillering, panicle initiation, panicle emergence and ripening). The results of this work showed that effect of different salinity levels on the all yield components except percentage of filled grains per panicle was not significant. Increase in salinity levels decreased this component. Effect of different growth stages on total number of empty grains per panicles, percentage of filled grains per panicle, number of unfilled panicles and percentage of ratio of number of unfilled panicles to tillers was significant but effect of different saline water on length of unfilled panicle and number of spikelets per unfilled panicle was insignificant. Resistance of final growth stages, i.e. panicle emergence and ripening stages against salinity was more than primary growth stages, i.e. tillering and panicle initiation. Therefore, in irrigation with saline water the final growth stages were important and irrigation with saline water should be applied at final growth stages.

Effect of inoculation with a thermotolerant plant growth promoting Pseudomonas putida strain AKMP7 on growth of wheat (Triticum spp.) under heat stress

The present study was carried out to investigate the effect of plant growth promoting thermotolerant Pseudomonas putida strain AKMP7 on the growth of wheat plants to heat stress. The results indicated the superior performance by P. putida strain AKMP7 in improving survival and growth of wheat plants under heat stress. The bacterium significantly increased the root and shoot length, dry biomass, tiller, spike let and grain formation of wheat over uninoculated plants. Inoculation reduced membrane injury and the activity of several antioxidant enzymes such as SOD, APX and CAT under heat stress. Inoculation improved the levels of cellular metabolites like proline, chlorophyll, sugars, starch, amino acids, and proteins compared to uninoculated plants. Scanning electron microscopy studies confirmed the colonization of the organism on the root surface. This result suggests the possible role of microorganisms in mitigating adverse effects of climate changes on crop growth and may lead to development of microbe based climate- ready technology.