scholarly journals DROUGHT TOLERANCE OF THE NEW SELF-POLLINATED LINES OF MAIZE AND THE METHODS OF ITS ESTIMATION

2021 ◽  
Vol 3 (27) ◽  
pp. 95-106
Author(s):  
G.Ya. Krivosheev ◽  
◽  
N.A. Shevchenko ◽  
A.S. Ignatiev ◽  
◽  
...  

More than half of the maize crops in the Russian Federation are located in areas with insufficient and unstable moisture. With this in mind, Z. mays breeding for drought tolerance is extremely important. The purpose of the current study is: investigate the drought tolerance of self-pollinated maize lines by various methods, identify the best samples for further breeding, establish indirect criteria for estimating drought tolerance. The study was conducted at the Agricultural Research Center “Donskoy” located in the southern part of the Rostov region, which is characterized by unstable moisture. The years of the study turned out to be dry (Selyaninov Hydrothermal Coefficient (HTC) = 0.32–0.89). The new self-pollinated lines of maize were used as initial material and studied for resistance to water stress (41 pcs. in 2011–2013, 39 pcs. in 2015–2017, 25 pcs. in 2018–2020). According to the guidelines for maize breeding, the following indicators of productivity were taken into account: number of ears per plant, weight of one ear, 1000-grain weight, number of grains per ear, etc. In 2011–2013, based on the comprehensive estimation, new middle-early drought-tolerant self-pollinated lines of maize ‘DK47111’, ‘SP203’, ‘KS211’, ‘S204’ and ‘S238’ were identified. They were characterized by the low values of residual water deficit both in the flowering (6.9 – 12.8%) and milk-wax (9.0 – 13.4%) stage, high drought tolerance index (68.6 – 85.6%), deep root system (force of uprooting the plants from the ground was 54.0–67.7 kgf), minimum gap in the flowering of male and female inflorescences (1–2 days). In 2015–2017, according to the method of residual water deficit (RWD), the following lines were identified ‘KV334’, ‘RD6’, ‘DS498/217-4’, ‘DS257/85-3’, ‘DS257/85-1’, ‘DS257/85-6’, ‘DS257/85-4’. In 2018–2020, the new self-pollinated lines of maize ‘KS317A’, ‘KV240’, ‘LSh16’, ‘S86’, ‘LSh17’ and ‘LSh2’ showed high resistance to water stress. We recommend the following selection criteria when creating new lines: absence of infertility and kernel percentage of the ears.

2021 ◽  
pp. 46-50
Author(s):  
G. Ya. Krivosheev ◽  
N. А. Shevchenko

The directions of the economic use of maize are different, namely fodder, food, technical. Considering that maize belongs to mesophytes, the most harmful stress factor for it is drought. The breeding maize for drought tolerance is considered the most important direction for this crop. The purpose of the current paper was to present study results of the drought resistance of the initial material, namely the self-pollinated maize lines and hybrids. The study was carried out at the Agricultural Research Center “Donskoy”, located in the zone of insufficient moisture in 2018–2020. Drought tolerance was determined by the method of residual water deficit (RWD). As an initial material, there were used 24 self-pollinated maize lines and 50 test-cross hybrids. There have been identified the new drought-resistant middle-early and middle-ripening self-pollinated lines ‘KS 317 A’,’ KV 240’, ‘LSh 16’, ‘S 86’, ‘LSh 17’ and ‘LSh 2’, ‘SP 246 / 276-2’, ‘DS 498 / 203-4’, ‘DS 298 / 203-3’, ‘DS 257 / 85-0’, ‘SP 280-3’, ‘KB 373’, which had a low residual water deficit in the flowering phase (7.7–10.4%) and did not significantly increase it during the period from vegetation to milky-wax ripeness (up to 10,3–12.6%). The drought-resistant hybrids include ‘Stepnyak MV’, ‘GK 26 AM × DS 257 / 85-0’, ‘P 101 × Zp 498 A’, ‘KB 399 × S 232’, ‘GK 26 AM × KB 373’, ‘GK 26 AM × SP 246 / 276-2’, ‘C 204 × KS 318’. They were characterized by a low water deficit during the flowering period (7.4–10.4%) and its low increase (1.4–3.7%) during the growing season. Drought-resistant hybrids, as a rule, included drought-resistant lines. According to the results of the State Variety Testing, the new middle-ripening three-line maize hybrid ‘Stepnyak MV’ ((KB 262 M × KB 326 ZM) × KB 498 MV)), developed on the basis of the drought-resistant lines ‘KB 262 M’ and ‘KB 498 MV’, has been included into the State Register since 2019. The hybrid possessed a high grain yield (4.55 t/ha) in the dry years of 2018–2020. it was characterized by high values of the main economically valuable traits, such as high resistance to lodging (0.5% of lodged plants), high starch content in grain (72.0%), optimum grain moisture (14.0%) by the harvesting time.


Author(s):  
A. M. M. Al-Naggar ◽  
M. M. Shafik ◽  
M. O. A. Elsheikh

Identifying maize genotypes with favorable root architecture traits for drought tolerance is prerequisite for initiating a successful breeding program for developing high yielding and drought tolerant varieties of maize. The aims of the present study were: (i) to identify drought tolerant genotypes of maize at flowering and grain filling, (ii) to interpret the correlations between the drought tolerance and root architecture traits and (iii) to identify the putative mechanisms of drought tolerance via root system traits. An experiment was carried out in two years using a split plot design with three replications. The main plots were assigned to three water stress levels, namely: well watering (WW), water stress at flowering (WSF) and water stress at grain filling (WSG), and sub-plots to 22 maize cultivars and populations. Drought tolerance index (DTI) had strong and positive associations with crown root length (CRL), root circumference (RC) and root dry weight (DRW) under both WSF and WSG, a negative correlation with brace root whorls (BW), and positive correlations with crown root number (CN) under WSF and brace root branching (BB) and crown root branching (CB) under WSG. These root traits are therefore considered as putative mechanisms of drought tolerance. The cultivars Pioneer-3444, SC-128, Egaseed-77, SC-10 and TWC-324 showed the most drought tolerant and the highest yielding in a descending order; each had a number of such drought tolerance mechanisms. Further investigation should be conducted to determine the underlying root mechanisms contributing to the selection of water-efficient hybrids of maize.


2021 ◽  
Vol 8 (3) ◽  
Author(s):  
A. M. Dhahi F.Y. Baktash

"ltural Research Ministry of Agriculture several drought indexes have been used to determine the best genotypes of (Triticum eastivum L.) for drought tolerance in the central region of Iraq, Determination of the efficacy of drought indexes for knowledge the genotypes of drought-tolerant and susceptibility and interpretation of the relationship between drought index used by primary component analysis, cluster analysis and rank sum. experiment was conducted to investigate water stress effect for the some traits of selected genotypes, using split plot arrangement within RCBD with 3 replications. The main plots included 2 levels of water stress (20% and 80%) depletion of available water while, the 9th selected genotypes and the control variety IPA99 occupied sub plots. The use of the best index of drought tolerance, MP, GMP and STI, led to the diagnosis of tolerant and stress-sensitive genotypes due to their association with grain yield in both stress and irrigation (YS and YP), The results of drought tolerance index showed that genotypes 186, 179 and 45 were the most tolerant of drought, while genotypes IPA 99, 117, 27 and 17 were the most sensitive to water stress and the other genotypes 44, 129, 147, middle tolerance or water stress sensitivity, Therefore, we recommend the cultivation of genotypes 186, 179 and 45 in the central region as they are most resistant to drought"


Agronomy ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1934
Author(s):  
Muhammad Sohail Saddiq ◽  
Xiukang Wang ◽  
Shahid Iqbal ◽  
Muhammad Bilal Hafeez ◽  
Shahbaz Khan ◽  
...  

Climate change scenarios predict that an extended period of drought is a real threat to food security, emphasizing the need for new crops that tolerate these conditions. Quinoa is the best option because it has the potential to grow under water deficit conditions. There is considerable variation in drought tolerance in quinoa genotypes, and the selection of drought-tolerant quinoa germplasms is of great interest. The main goal of this work is to evaluate the crop yield and characterize the physiology of 20 quinoa genotypes grown under water deficit in a wirehouse. The experiment was a complete randomized design (CRD) factorial with three replications. Seedling growth, i.e., fresh weight (FW), dry weight (DW), root length (RL), shoot length (SL), relative growth rate of root length (RGR-RL), shoot length (RGR-SL), and physiological performance, i.e., chlorophyll content (a and b), carotenoid, leaf phenolic content, leaf proline content, membrane stability index (MSI), and leaf K+ accumulation were evaluated in a hydroponic culture under different water-deficit levels developed by PEG 6000 doses (w/v) of 0% (control), 0.3%, and 0.6%. Yield attributes were evaluated in a pot at three different soil moisture levels, as determined by soil gravimetric water holding capacity (WHC) of 100 (control), 50% WHC (50 % drought stress) and 25% WHC (75% stress). In both experiments, under the water stress condition, the growth (hydroponic study) and yield traits (pot study) were significantly reduced compared to control treatments. On the drought tolerance index (DTI) based on seed yield, genotype 16 followed by 10, 1, 4, 5, 7, and 12 could be considered drought-tolerant genotypes that produced maximum grain yield and improved physiological characteristics under severe water stress conditions in hydroponic culture. In both studies, genotypes 3, 8, 13, and 20 performed poorly and were considered drought-sensitive genotypes with the lowest DTI values under water-stressed conditions. All the studied agronomic traits (grain yield, root and shoot length, shoot fresh and dry weights) and physiological traits (leaf phenolic, proline content, carotenoid, K+ accumulation, membrane stability index, and relative water content) were firmly inter-correlated and strongly correlated with DTI. They can be regarded as screening criteria, employing a large set of quinoa genotypes in a breeding program.


Plants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 27
Author(s):  
Mahmoud M. Gaballah ◽  
Azza M. Metwally ◽  
Milan Skalicky ◽  
Mohamed M. Hassan ◽  
Marian Brestic ◽  
...  

Drought is the most challenging abiotic stress for rice production in the world. Thus, developing new rice genotype tolerance to water scarcity is one of the best strategies to achieve and maximize high yield potential with water savings. The study aims to characterize 16 rice genotypes for grain and agronomic parameters under normal and drought stress conditions, and genetic differentiation, by determining specific DNA markers related to drought tolerance using Simple Sequence Repeats (SSR) markers and grouping cultivars, establishing their genetic relationship for different traits. The experiment was conducted under irrigated (normal) and water stress conditions. Mean squares due to genotype × environment interactions were highly significant for major traits. For the number of panicles/plants, the genotypes Giza179, IET1444, Hybrid1, and Hybrid2 showed the maximum mean values. The required sterility percentage values were produced by genotypes IET1444, Giza178, Hybrid2, and Giza179, while, Sakha101, Giza179, Hybrid1, and Hybrid2 achieved the highest values of grain yield/plant. The genotypes Giza178, Giza179, Hybrid1, and Hybrid2, produced maximum values for water use efficiency. The effective number of alleles per locus ranged from 1.20 alleles to 3.0 alleles with an average of 1.28 alleles, and the He values for all SSR markers used varied from 0.94 to 1.00 with an average of 0.98. The polymorphic information content (PIC) values for the SSR were varied from 0.83 to 0.99, with an average of 0.95 along with a highly significant correlation between PIC values and the number of amplified alleles detected per locus. The highest similarity coefficient between Giza181 and Giza182 (Indica type) was observed and are susceptible to drought stress. High similarity percentage between the genotypes (japonica type; Sakha104 with Sakha102 and Sakha106 (0.45), Sakha101 with Sakha102 and Sakha106 (0.40), Sakha105 with Hybrid1 (0.40), Hybrid1 with Giza178 (0.40) and GZ1368-S-5-4 with Giza181 (0.40)) was also observed, which are also susceptible to drought stress. All genotypes are grouped into two major clusters in the dendrogram at 66% similarity based on Jaccard’s similarity index. The first cluster (A) was divided into two minor groups A1 and A2, in which A1 had two groups A1-1 and A1-2, containing drought-tolerant genotypes like IET1444, GZ1386-S-5-4 and Hybrid1. On the other hand, the A1-2 cluster divided into A1-2-1 containing Hybrid2 genotype and A1-2-2 containing Giza179 and Giza178 at coefficient 0.91, showing moderate tolerance to drought stress. The genotypes GZ1368-S-5-4, IET1444, Giza 178, and Giza179, could be included as appropriate materials for developing a drought-tolerant variety breeding program. Genetic diversity to grow new rice cultivars that combine drought tolerance with high grain yields is essential to maintaining food security.


2019 ◽  
Vol 02 ◽  
pp. 65-70
Author(s):  
Tin Q. Huynh

Drought has been a big problem and damaged seriously to rice cultivation and production in Vietnam and the Mekong Delta region; evaluating drought tolerance of rice is a major objective for the rice improvement programmes in Can Tho University. Fifty-two collected rice varieties including resistant and susceptible control varieties were screened for water stress under the artificial drought condition. Marker RM223 was used to identify the drought tolerance genotypes for some selected varieties with good and moderate tolerant scores. After 30 days of water stress, the results were 6 varieties of good tolerant, 8 varieties of moderate tolerance, 36 varieties of moderately susceptible and 2 varieties of susceptible to drought. Analyses of PCR showed that 10 varieties expressed the similar bands with the resistant control variety. Four varieties (LH8, MTL812, Lua Canh and VB1) with good tolerant to drought were recommended to use for genetic materials of rice breeding program and applying in alternative wetting and drying irrigation technique for rice cultivation.


2018 ◽  
Vol 10 (4) ◽  
pp. 575-583 ◽  
Author(s):  
Fereshteh JOKAR ◽  
Rahmatollah KARIMIZADEH ◽  
Asad MASOUMIASL ◽  
Reza AMIRI FAHLIANI

Durum wheat (Triticum durum L.) is used for the preparation of multiple food products, including pasta and bread. Its production is restricted due to diverse environmental stresses i.e. drought and heat stress. Here, comparative analysis of durum wheat varieties was done by studying canopy temperature depression (CTD) and chlorophyll content (CHL), yield and yield contributing traits to evaluate their performance under stress and low stress conditions. Twelve durum wheat genotypes were studied under stressful and low-stress conditions in Gachsaran region of Iran. CTD and CHL were measured at two stages, from the emergence of fifty percent of inflorescence (ZGS 54) to watery ripe stage (ZGS 71). According to stress tolerance index (STI), mean productivity (MP) and geometric mean productivity (GMP) indices, genotype G10 exhibited the most, while genotype G6, the least relative tolerance, respectively. Based on MP and GMP, genotype G10 was found to be drought tolerant, while genotype G2 displayed the lowest amount of MP and GMP. Therefore these genotypes are recommended to be used as genitors in artificial hybridization for improvement of drought tolerance in other cultivars. All indices had high correlation with grain yield under stress and non-stress condition, indicating more suitability of these indices for selection of resistant genotype. Results of the present study showed that among drought tolerance indices, harmonic mean (HM), GMP, CTD and modified STI index (K2STI) can be used as the most suitable indicators for screening drought tolerant cultivars.


2020 ◽  
Vol 41 (4) ◽  
pp. 1093
Author(s):  
Suerlani Aparecida Ferreira Moreira ◽  
Pablo Fernando Santos Alves ◽  
Carlos Eduardo Corsato ◽  
Alcinei Mistico Azevedo

Maize hybrids contrasting for drought tolerance differ during the vegetative stage. Drought is the main constraint on maize production in developing nations. Differences during development between genetic materials of maize grown under water restriction suggest that the plant can be improved with a view to its adaptation. In maize, sensitivity to water stress can occur at any stage of its phenological development. However, few studies report its effects on the vegetative phase of the cycle. On this basis, this study was conducted to examine how shoot and root-system indices are expressed in cultivation under water deficit as well as determine which indicators best explain the difference between hybrids in the evaluated water regimes. Commercial seeds of hybrids BR1055 and DKB-390 (drought-tolerant) and BRS1010 (drought-sensitive) were germinated in PVC tubes (1.0 m × 0.1 m) in a randomized complete block design, in a 3 × 2 factorial arrangement. The experiment was developed in a greenhouse where two water regimes were tested: no water stress and with water stress from the VE stage. The soil consisted of quartz sand mixed with a commercial fertilizer. Stem and root traits were evaluated up to the V5 growth stage. Relative chlorophyll content, leaf temperature, stem length, phenology, shoot dry biomass, root length, root dry biomass, root surface area, root volume and D95 were responsive to water deficit. The parameters that allowed the distinction between the hybrids in water the regimes were relative chlorophyll content, leaf temperature, phenology and average root diameter.


Agronomy ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 371 ◽  
Author(s):  
Isabella Mendonça Arruda ◽  
Vânia Moda-Cirino ◽  
Alessandra Koltun ◽  
Douglas Mariani Zeffa ◽  
Getúlio Takashi Nagashima ◽  
...  

Water stress is one of the main limiting factors for common bean crops, negatively affecting grain yield and seed quality. Thus, the objective of this study was to evaluate the inheritance of agromorphological and physiological traits related to drought tolerance in order to identify promising combinations. The experiment was carried out in a greenhouse with a partial diallel scheme between three drought-tolerant genotypes (IAPAR 81, BAT 477. and SEA 5), and nine cultivars widely grown in Brazil (BRS Estilo, IAC Alvorada, IPR Campos Gerais, IPR Uirapuru, IPR Nhambu, BRS Esteio, IPR Garça, BRS Radiante, and DRK 18), in a randomized block design with four replicates. The plants were grown in pots with substrate under 80% of pot capacity until they reached the stage R5, when water supply was restricted to 30% for 20 days in the pots under stress treatment. A wide variability for the agromorphological and physiological traits was observed. Water deficit reduced plant performance for most agromorphological traits and altered their physiological metabolism. Additive and non-additive effects are involved in the genetic control of the majority of agromorphological and physiological traits both under water stress and control (well-watered) conditions. The parental genotypes BAT 477 (group I) and IAC Alvorada, IPR Uirapuru, and BRS Esteio (group II) may be included in breeding programs aiming at improving drought tolerance in common bean since they present high positive general combining abilities for agromorphological traits. The crosses IAPAR 81 × IPR Campos Gerais, and SEA 5 × BRS Radiante resulted in the best combinations considering grain yield per plant and total dry biomass, when cultivated under water deficit.


Genome ◽  
2021 ◽  
Vol 64 (1) ◽  
pp. 15-27
Author(s):  
Fan Qiu ◽  
Seton Bachle ◽  
Ryan Estes ◽  
Melvin R. Duvall ◽  
Jesse B. Nippert ◽  
...  

Water stress associated with drought-like conditions is a major factor limiting plant growth and impacts productivity of natural plant communities and agricultural crops. Molecular responses of plants to water stress have been studied most extensively in model species and crops, few of which have evolved natural drought tolerance. In the current study, we examined physiological and transcriptomic responses at multiple timepoints during increasing water stress and following initial recovery from stress in a drought-tolerant C3 species, Festuca ovina. Results demonstrated non-linear transcriptomic changes during increasing stress, but largely linear declines in physiological measurements during this same period. Transcription factors represented approximately 12.7% of all differentially expressed genes. In total, 117 F. ovina homologs of previously identified and molecularly characterized drought-responsive plant genes were identified. This information will be valuable for further investigations of the molecular mechanisms involved in drought tolerance in C3 plants.


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