scholarly journals A Novel Stay-Green Mutant of Rice with Delayed Leaf Senescence and Better Harvest Index Confers Drought Tolerance

Plants ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 375 ◽  
Author(s):  
M. K. Ramkumar ◽  
S. Senthil Kumar ◽  
Kishor Gaikwad ◽  
Rakesh Pandey ◽  
Viswanathan Chinnusamy ◽  
...  

Three Ethyl methansulphonate (EMS)-induced stay-green mutants (SGM-1, SGM-2 and SGM-3) and their wild-type (WT), were tested for their Stay-Green (SG) and drought tolerance nature as the relation between these two attributes is not yet established in rice. In the dark induced senescence assay, SGM-3 showed delayed senescence while SGM-1 and SGM-2 showed complete lack of senescence. Mutants showed stable transcript abundance over time, for 15 candidate genes (CGs) associated with senescence, compared to the WT. SGM-3 however showed moderately increasing transcript abundance over time for ATG6a, ATG4a, NYC1, NOL and NYC3. Only SGM-3 performed better than the WT for yield and harvest index under well irrigated as well as drought conditions, though all the mutants showed better performance for other agronomic traits under both the conditions and ascorbate peroxidase activity under drought. Thus, SG trait showed positive correlation with drought tolerance though only SGM-3 could convert this into higher harvest index. Sequence analysis of 80 senescence-associated genes including the 15 CGs showed non-synonymous mutations in four and six genes in SGM-1 and SGM-2 respectively, while no SNPs were found in SGM-3. Analysis of the earlier reported Quantitative Trait Loci (QTL) regions in SGM-3 revealed negligible variations from WT, suggesting it to be a novel SG mutant.

Genes ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 1026 ◽  
Author(s):  
K. N. S. Usha Kiranmayee ◽  
C. Tom Hash ◽  
S. Sivasubramani ◽  
P. Ramu ◽  
Bhanu Prakash Amindala ◽  
...  

This study was conducted to dissect the genetic basis and to explore the candidate genes underlying one of the important genomic regions on an SBI-10 long arm (L), governing the complex stay-green trait contributing to post-flowering drought-tolerance in sorghum. A fine-mapping population was developed from an introgression line cross—RSG04008-6 (stay-green) × J2614-11 (moderately senescent). The fine-mapping population with 1894 F2 was genotyped with eight SSRs and a set of 152 recombinants was identified, advanced to the F4 generation, field evaluated with three replications over 2 seasons, and genotyped with the GBS approach. A high-resolution linkage map was developed for SBI-10L using 260 genotyping by sequencing—Single Nucleotide Polymorphism (GBS–SNPs). Using the best linear unpredicted means (BLUPs) of the percent green leaf area (%GL) traits and the GBS-based SNPs, we identified seven quantitative trait loci (QTL) clusters and single gene, mostly involved in drought-tolerance, for each QTL cluster, viz., AP2/ERF transcription factor family (Sobic.010G202700), NBS-LRR protein (Sobic.010G205600), ankyrin-repeat protein (Sobic.010G205800), senescence-associated protein (Sobic.010G270300), WD40 (Sobic.010G205900), CPK1 adapter protein (Sobic.010G264400), LEA2 protein (Sobic.010G259200) and an expressed protein (Sobic.010G201100). The target genomic region was thus delimited from 15 Mb to 8 genes co-localized with QTL clusters, and validated using quantitative real-time (qRT)–PCR.


Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 354
Author(s):  
El-Sayed M. Desoky ◽  
Elsayed Mansour ◽  
Mohamed M. A. Ali ◽  
Mohamed A. T. Yasin ◽  
Mohamed I. E. Abdul-Hamid ◽  
...  

The influence of 24-epibrassinolide (EBR24), applied to leaves at a concentration of 5 μM, on plant physio-biochemistry and its reflection on crop water productivity (CWP) and other agronomic traits of six maize hybrids was field-evaluated under semi-arid conditions. Two levels of irrigation water deficiency (IWD) (moderate and severe droughts; 6000 and 3000 m3 water ha−1, respectively) were applied versus a control (well-watering; 9000 m3 water ha−1). IWD reduced the relative water content, membrane stability index, photosynthetic efficiency, stomatal conductance, and rates of transpiration and net photosynthesis. Conversely, antioxidant enzyme activities and osmolyte contents were significantly increased as a result of the increased malondialdehyde content and electrolyte leakage compared to the control. These negative influences of IWD led to a reduction in CWP and grain yield-related traits. However, EBR24 detoxified the IWD stress effects and enhanced all the above-mentioned parameters. The evaluated hybrids varied in drought tolerance; Giza-168 was the best under moderate drought, while Fine-276 was the best under severe drought. Under IWD, certain physiological traits exhibited a highly positive association with yield and yield-contributing traits or CWP. Thus, exogenously using EBR24 for these hybrids could be an effective approach to improve plant and water productivity under reduced available water in semi-arid environments.


Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1427
Author(s):  
Gulen Ozyazici

Environmental contamination and the excessive use of inorganic fertilizers resulting in stagnant yields of field crops which necessitate the utilization of combined fertilization approach under changing climatic conditions. Current study was aimed to clarify the influence of several fertilizer sources (chemical, organic, organomineral fertilizers) on yield and quality of coriander (Coriandrum sativum L.). The results revealed that the fertilizer sources significantly affected the yield of coriander cultivars. The absence of “Year x Variety x Fertilizer Type” interactions for any of the noted parameters signaled that the detected “Variety x Fertilizer Type” interactions were constant regardless of the year factor. The recorded values of traits according to fertilizer sources different for the plant height from 61.85 to 69.67 cm, number of branches from 5.98 to 7.71 (piece/plant), number of umbels per the main umbel from 5.62 to 7.18 pieces, seed yield from 1.06 to 1.66 t/ha, the biological yield from 4.29 to 5.70 t ha−1, harvest index from 25.29 to 29.41%, essential oil ratio from 0.29 to 0.33%, and essential oil yield from 3.1 to 5.6 L ha−1. Erbaa variety was observed to be superior over the rest of the varieties producing the maximum values of 6.5 L ha−1 of essential oil, 0.36% essential oil content, 30.9% harvest index, 1.81 t/ha seed yield, and 5.9 t ha−1 biological yield with the treatment of chemical fertilizers.


2011 ◽  
Vol 91 (1) ◽  
pp. 37-48 ◽  
Author(s):  
M. Cogliatti ◽  
F. Bongiorno ◽  
H. Dalla Valle ◽  
W J Rogers

Fifty-seven accessions of canaryseed (47 populations and 10 cultivars) from 19 countries were evaluated for agronomic traits in four field trials sown over 3 yr in the province of Buenos Aires, Argentina. Genetic variation was found for all traits scored: grain yield and its components (grain weight, grain number per square meter, grain number per head and head number per square meter), harvest index, percent lodging, and phenological characters (emergence to heading, emergence to harvest maturity and heading to harvest maturity). Although genotype × environment interaction was observed for all traits, the additive differences between accessions were sufficient to enable promising breeding materials to be identified. Accessions superior in performance to the local Argentinean population, which in general gave values close to the overall mean of the accessions evaluated, were identified. For example, a population of Moroccan origin gave good yield associated with elevated values of the highly heritable character grain weight, rather than with the more commonly observed grain number per square meter. This population was also of relatively short stature and resistant to lodging, and, although it performed best when sown within the normal sowing date, tolerated late sowing fairly well. Other accessions were also observed with high grain weight, a useful characteristic in itself, since large grains are desirable from a quality point of view. Regarding phenology, the accessions showed a range of 160 degree days (8 calendar days in our conditions) in maturity, which, while not large in magnitude, may be of some utility in crop rotation management. Some accessions were well adapted to late sowing. Grain yield in general was strongly correlated with grain number per square meter. Principal components analysis (PCA) carried out for all characteristics provided indications of accessions combining useful characteristics and identified three components that explained approximately 70% of the phenotypic variation. Furthermore, a second PCA plus regression showed that approximately 60% of the variation in grain yield could be explained by a component associated with harvest index and grain number per square meter. Pointers were provided to possible future breeding targets.Key words: Phalaris canariensis, canaryseed, accessions, yield, phenology, genetics, breeding


EDIS ◽  
1969 ◽  
Vol 2004 (4) ◽  
Author(s):  
Laurie E. Trenholm ◽  
Joseph Bryan Unruh

Most homeowners over-water their lawns, which may damage or kill the lawn over time. Excess irrigation is one of the major causes of lawn demise and may include problems such as a shallow root system; increased disease, weed, or insect infestation; reduced drought tolerance; increased thatch and excessive growth; and reduced tolerance to other stresses such as shade and soil problems. To avoid over-watering, look for signs that the lawn needs water. This document is ENH63, one of a series of the Department of Environmental Horticulture, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Dates reviewed: March 2000; September 2003. https://edis.ifas.ufl.edu/ep054


2021 ◽  
Author(s):  
Weiwei Gao ◽  
Mingkang Li ◽  
Songguang Yang ◽  
Chunzhi Gao ◽  
Yan Su ◽  
...  

AbstractInduced abscisic acid (ABA) biosynthesis plays an important role in plant tolerance to abiotic stresses, including drought, cold and salinity. However, regulation pathway of the ABA biosynthesis in response to stresses is unclear. Here, we identified a rice miRNA, osa-miR2105 (miR2105), which plays a crucial role in ABA biosynthesis under drought stress. Analysis of expression, transgenic rice and cleavage site showed that OsbZIP86 is a target gene of miR2105. Subcellular localization and luciferase activity assays showed that OsbZIP86 is a nuclear transcription factor. In vivo and in vitro analyses showed that OsbZIP86 directly binds to the promoter of OsNCED3, and interacts with OsSAPK10, resulting in enhanced-expression of OsNCED3. Transgenic rice plants with knock-down of miR2105 or overexpression of OsbZIP86 showed higher ABA content, more tolerance to drought, a lower rate of water loss, more stomatal closure than wild type rice ZH11 under drought stress. These rice plants showed no penalty with respect to agronomic traits under normal conditions. By contrast, transgenic rice plants with miR2105 overexpression, OsbZIP86 downregulation, or OsbZIP86 knockout displayed less tolerance to drought stress and other phenotypes. Collectively, our results show that a regulatory network of ‘miR2105-OsSAPK10/OsbZIP86-OsNCED3’ control ABA biosynthesis in response to drought stress.One-sentence summary‘miR2105-OsbZIP86-OsNCED3’ module plays crucial role in mediating ABA biosynthesis to contribute to drought tolerance with no penalty with respect to agronomic traits under normal conditions.


2017 ◽  
Vol 9 (9) ◽  
pp. 182
Author(s):  
Abdullah M. Algosaibi ◽  
Ayman E. Badran ◽  
Abdulrahman M. Almadini ◽  
Mohammed M. El-Garawany

This experiment was conducted to study the effect of irrigation intervals on growth, yield and its components and some of the chemical characteristics of the soil after the harvest of quinoa (Chenopodium quinoa willd) plant. Three treatments were used as follow: T1 (twice irrigation every week, which is the common in the region), T2 (once irrigation every week) and T3 (twice irrigation every two weeks) using in a randomized complete block design with four replicates. The crop coefficient (Kc) value differed according to the stage of growth where the results showed that the T2 treatment gave the highest mean in all the studied traits followed by the T3 treatment in all traits except the number of seed/m2. The results also confirmed that the increase in water reduced the agronomic traits such as harvest index, number of seeds and yield of seeds and straw/m2. Also it showed that the pH values in soils were not significantly affected by irrigation, while Ec significantly affected. Correlation coefficient was negative with the most traits and low with the number of grain (0.34) under overall studied treatments which confirms that quinoa is a plant that needs limited amounts of irrigation water. On the other hand there was positive strong correlation between the harvest index and grain yield (0.92). The results showed that moisture stress treatments increased the concentration of the ionic, NH4-N and NO3-N significantly compared to soils which do not have moisture stress (T1, T2). We assume that the development based on Kc during growth-stages helps in irrigation management and provides precise water applications for quinoa plant. These results indicate that the water requirements of quinoa plant are limited and that quinoa plant growth is not affected by the lack of irrigation water on the crop and its qualities.


2018 ◽  
Vol 46 (1) ◽  
pp. 65-74 ◽  
Author(s):  
José F.T. GANANÇA ◽  
José G.R. FREITAS ◽  
Humberto G.M. NÓBREGA ◽  
Vanessa RODRIGUES ◽  
Gonçalo ANTUNES ◽  
...  

Taro [Colocasia esculenta (L.) Schott] is a root crop which is an important staple food in many regions of the world, producing 10.5 million tonnes on 1.4 million hectares a year. The crop is cultivated in wet (rain fed) or irrigated conditions, requiring on average 2,500 mm water per year, and in many countries it is cultivated in flooded plots. It is estimated that taro production could decrease by 40% as a result of the increase in drought and other severe events. In this work, thirty three accessions, including local cultivars, selected and hybrid lines were submitted to long duration drought stress and screened for tolerance. Twelve physiological, morphological and agronomic traits were measured at harvest, and subject to multivariate analysis. Stress indices, Water Use Efficiency and Factorial Analysis were useful for discriminating accessions regarding drought tolerance and yield stability, and drought tolerant and susceptible cultivars were identified. Our results confirm that different taro cultivars have different drought avoidance and tolerance strategies to cope with water scarcity. Better yield performers minimised biomass and canopy loss, while tolerance was observed in cultivars that presented low potential yield, but efficiently transferred resources to enhance corm formation. Among the 33 accessions, two local cultivars showed high yield stability and could be considered as suitable parents for breeding programs, while two others are well adapted to drought, but with overall low yield potential.


2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Ali Mansouri ◽  
Bachir Oudjehih ◽  
Abdelkader Benbelkacem ◽  
Zine El Abidine Fellahi ◽  
Hamenna Bouzerzour

Relationships among agronomic traits and grain yield were investigated in 56 genotypes of durum wheat (Triticum durumDesf.). The results indicated the presence of sufficient variability nearly for all measured traits. Heritability and expected genetic gain varied among traits. Aboveground biomass, harvest index, and spike number were the most grain yield-influencing traits. Early genotypes showed above-average grain and biological yields, spike number, and lower canopy temperature. Assessed genotypes were clustered into three groups which differed mainly for biological, economical, straw, and grain yields, on the one hand, and plant height, chlorophyll content, and canopy temperature, on the other hand. Selection for direct use from clusters carrying best combinations of yield-related traits and crosses to be made between genotypes belonging to contrasted clusters were suggested to generate more variability. Selection preferentially for spike number, biological yield, harvest index, and canopy temperature to accumulate favorable alleles in the selected entries for future uses is suggested.


2001 ◽  
Vol 48 (4) ◽  
pp. 353-361 ◽  
Author(s):  
E. Farshadfar ◽  
M. Farshadfar ◽  
J. Sutka

To study the properties of some drought tolerance criteria and  agronomic characters in wheat, an eight-parental diallel cross, excluding reciprocals, was grown in a randomized complete block design with three replications under two different water regimes (irrigated and rainfed) for two years in the College of Agriculture at Razi University, Kermanshah, Iran. High broad-sense heritability estimates were observed for harvest index, grain yield, and earliness. Additive gene action was found to be predominant for grain yield, harvest index, relative water content and chlorophyll fluorescence. The results of combining ability analysis revealed that Plainsman was the best general combiner and Plainsman × Kobomugi was the best specific combination for improving drought tolerance. The pooled analysis of variance for combining ability over rainfed conditions reflected that the GCA × environment interaction was not significant for harvest index and chlorophyll fluorescence, and the SCA × environment interaction was  non-significant for relative water content and relative water loss, indicating that genes controlling osmoregulation and the other physiological traits mentioned are not affected in these varieties by different rainfed conditions and hence show static stability.


Sign in / Sign up

Export Citation Format

Share Document