Screening Of Cultivars Research Articles

Rapid Screening of Traditional Rice Cultivars against Drought Using Tolerance Indices of Seedlings

Aim: To screen the traditional cultivars of rice based on the tolerance indices of seedling characteristics. Study Design: The experimental plan used was Complete Randomized Design with 59 treatments (genotypes) and two replications. Place of Study: P.G. Laboratory, Department of Seed Science and Technology, Uttar Banga Krishi Viswavidyalaya, Pundibari, Cooch Behar district, West Bengal, India. Methodology: Seedling was raised in glass in two sets- PEG-mediated drought and normal conditions. Results: All the seedling characters showed highly significant differences among the varieties, different culture conditions as well as interaction between varieties and environment. Most of the cultivars exhibited reduction in number of primary roots per plant, root length, root fresh weight, root dry weight, shoot length, shoot fresh weight and shoot dry weight. Finally the cultivars were grouped under three categories- tolerant, semi-tolerant and susceptible based on mean tolerance index (MTI). The cultivars having ≥ 90.00, MTI Kashiya binni, Jhagri kartik and Garu Chakua were considered as tolerant. Among those three cultivars, Kashiya binni was found to be highly tolerant to drought as its MTI was ≥ 100.00 (114.96). Subsequently 22 cultivars were classified as semi-tolerant. In conclusion, the tolerance indices of seedling traits and subsequently the MTI can be used for rapid screening of rice genotypes for water stress.

Screening of rice cultivars against Scirpophaga incertulas Walker : utilising cluster analysis as a tool to identify resistant cultivars

The field experiment was conducted in the Boro season from December 2022 to April 2023 at the Institutional research farm, Institute of Agriculture, Palli Siksha Bhavana, Visva-Bharati, Sriniketan, Birbhum, West Bengal, for the screening of thirty-three rice cultivars for their resistance to yellow stem borer, Scirpophaga incertulas Walker. The experiment utilized modified percent damage values to grade these cultivars during both vegetative and reproductive stages. Early-duration cultivars displayed varied reactions, with Jaldi 13 (2) exhibiting consistent resistance (2.53% DH, 12.65% D), while others showed moderate resistance or susceptibility with deadheart percentages ranging from 4.73% to 8.51% and corresponding damage percentages between 23.65% and 42.55%. This trend extended to reproductive stages, where all early-duration cultivars demonstrated moderate to high susceptibility, with damage percentages between 30.8% and 54.5%. The mid-early duration cultivars displayed mixed responses, with Sahabhagi (4) demonstrating moderate resistance (4.92% DH) and Sukumar (3) exhibiting moderate susceptibility (8.21% DH) during the vegetative stage. These diverse reactions continued into the reproductive stage, providing a comprehensive understanding of their responses to the pest. Additionally, in medium and late-duration cultivars, a range of reactions persisted, with cultivars like Pratiksha (20) showing moderate resistance (6.63% DH) in the mid-duration category and Ajith (25) displaying moderate resistance (6.33% DH) in the late-duration category. Cluster analysis categorized the cultivars into distinct groups, showcasing a mix of resistant, moderately resistant, and susceptible types across all growth durations. Notably, cultivars like Gotra 1 (10), Parijat (14), Pushpa (17), PNR 546 (19), Pravat (23) and Gotra 2 (31) consistently demonstrated resistance or moderate resistance across different growth stages, suggesting their potential suitability in tailoring resistant breeding programs and pest management strategies against the stem borer in rice cultivation.

Investigating the utility of potato (Solanum tuberosum L.) canopy temperature and leaf greenness responses to water-restriction for the improvement of irrigation management

Traits that rapidly respond to stress in important agricultural crops have the potential to provide growers with actionable feedback. Traits that respond to water-restriction could inform irrigation systems by identifying crop water status and requirements in real-time. This would be particularly useful for potato, which is extremely susceptible to drought. We conducted two pot experiments and one field experiment to evaluate the utility of two traits, canopy temperature and leaf greenness, for informing irrigation management in potatoes. We also evaluated the efficacy of Phenospex PlantEye F500 sensors for the remote sensing of leaf greenness. We found that canopy temperatures of the cvs. Maris Piper (Spring Pot Experiment, + 0.8 °C; Autumn Pot Experiment, + 5.3 °C) and Désirée (Autumn Pot Experiment, + 2.5 °C) increased with water-restriction and that the canopy temperatures of Maris Piper returned to its baseline within three days after the resumption of well-watered conditions. We also found that these responses varied between cultivars, with predictable outcomes based on reported and corroborated drought tolerance ratings. Leaf greenness was not affected by water restriction in the Spring pot experiment but had a significant interaction with sampling date and water restriction in the Autumn pot experiment. However, leaf greenness measurements from the Phenospex PlantEye F500 were significantly correlated with SPAD values, suggesting this tool might be useful in the screening for drought-tolerant cultivars in the future.

Remote sensing for estimating genetic parameters of biomass accumulation and modeling stability of growth curves in alfalfa.

Multi-spectral imaging by unoccupied aerial vehicles provides a non-destructive, high throughput approach to measuring biomass accumulation over successive alfalfa (Medicago sativa L. subsp. sativa) harvests. Information from estimated growth curves can be used to infer harvest biomass and to gain insights into the relationship between growth dynamics and forage biomass stability across cuttings and years. In this study, multi-spectral imaging and several common vegetation indices were used to estimate genetic parameters and model growth of alfalfa cultivars to determine the longitudinal relationship between vegetation indices and forage biomass. Results showed moderate heritability for vegetation indices, with median plot level heritability ranging from 0.11-0.64, across multiple cuttings in three trials planted in Ithaca, NY, and Las Cruces, NM. Genetic correlations between the normalized difference vegetation index and forage biomass were moderate to high across trials, cuttings, and the timing of multi-spectral image capture. To evaluate the relationship between growth parameters and forage biomass stability across cuttings and environmental conditions, random regression modeling approaches were used to estimate the growth parameters of cultivars for each cutting and the variance in growth was compared to the variance in genetic estimates of forage biomass yield across cuttings. These analyses revealed high correspondence between stability in growth parameters and stability of forage yield. The results of this study indicate that vegetation indices are effective at modeling genetic components of biomass accumulation, presenting opportunities for more efficient screening of cultivars and new longitudinal modeling approaches that can provide insights into temporal factors influencing cultivar stability.

Vascular streak dieback: A novel threat to redbud and other woody ornamental production in the United States.

Eastern redbud (Cercis canadensis L.) is a popular and high-value woody ornamental plant native to the eastern and south-central United States of America (U.S.A.). In recent years, redbud production in the Southeastern U.S.A. has been greatly affected by a novel threat: vascular streak dieback (VSD). Infected plants exhibit a common set of symptoms, including leaf scorch, tip dieback, and vascular streaking that creates a marbled pattern in stem cross-section. Based on both conventional diagnosis and molecular identification, it has been found that the fungus Ceratobasidium sp. D.P. Rogers (Csp) is consistently associated with VSD-symptomatic eastern redbuds. However, the causal agent(s) of VSD has not yet been conclusively confirmed. Although eastern redbud has been the most frequently identified host tree, more than 25 other native plant genera have been confirmed to have VSD associated with Csp. The near-obligate nature of this fungus has made it challenging to culture, extract DNA, and conduct further studies to confirm its pathogenicity. This article highlights the emerging challenges of VSD, focusing on the following: 1) the recent history of VSD; 2) the increasing importance of VSD to woody ornamental nursery production in the U.S.A.; 3) the currently available protocols for isolating, culturing, storing, and maintaining the putative causal agent; 4) the rapid molecular detection of Csp; 5) phylogenetic findings on the origin and relatedness of Csp to previously recorded diseases, especially VSD in cacao (Theobroma cacao L.); and 6) preliminary results and observations from fungicide trials and cultivar screening in Tennessee. The article also outlines research needed to comprehensively understand VSD and accelerate the development of effective management strategies.

Both Short-term and Long-term Ozone Pollution Alters the Chemical Composition of rice Grain.

The increasing ground-level ozone (O3) is threatening food security, especially in Asian areas, where rice is one of the most important staple crops. O3 impacts on rice could be exacerbated by its spatiotemporal heterogeneity. To improve evaluation accuracy and develop effective adaptations, direct data is urgently needed. Studies on the short-term effects of O3 on rice grain, however, are lacking. Which may lead to an underestimation of the O3 impacts. Through a field experiment, we studied the responses of grain nitrogen, grain carbon, and grain protein in rice cultivars to elevated concentrations of O3 (40 ppb plus that in background air, eO3), especially examining the effects of short-term eO3 during different plant growth stages. We found that long-term eO3 increased grain nitrogen by 29.29% in a sensitive rice cultivar, and short-term eO3 at the tillering and jointing stages increased grain nitrogen by 19.31%, and the grain carbon to nitrogen ratio was decreased by 14.70%, and 21.14% by short-term and long-term eO3. Here we demonstrate that short-term eO3 may significantly affect the chemical composition of rice grains. Previous evaluations of the effects of eO3 may be underestimated. Moreover, changes in the grain nitrogen and grain protein were greater when the short-term eO3 was added to rice plants during the tillering and jointing stage, compared to heading and ripening stage. These results suggest that to improve the tolerance of rice to eO3 to achieve food security, studies on cultivar screening, as well as developing growth-stage-specific adaptations are needed in future.

Screening of Pepper and Tomato Grafted Seedling Cultivars for Intumescence Susceptibility

Screening of Pepper and Tomato Grafted Seedling Cultivars for Intumescence Susceptibility

Review on blueberry drought tolerance from the perspective of cultivar improvement.

Blueberry (Vaccinium spp.) is an increasingly popular fruit around the world for their attractive taste, appearance, and most importantly their many health benefits. Global blueberry production was valued at $2.31 billion with the United States alone producing $1.02 billion of cultivated blueberries in 2021. The sustainability of blueberry production is increasingly threatened by more frequent and extreme drought events caused by climate change. Blueberry is especially prone to adverse effects from drought events due to their superficial root system and lack of root hairs, which limit blueberry's ability to intake water and nutrients from the soil especially under drought stress conditions. The goal of this paper is to review previous studies on blueberry drought tolerance focusing on physiological, biochemical, and molecular drought tolerance mechanisms, as well as genetic variability present in cultivated blueberries. We also discuss limitations of previous studies and potential directions for future efforts to develop drought-tolerant blueberry cultivars. Our review showed that the following areas are lacking in blueberry drought tolerance research: studies of root and fruit traits related to drought tolerance, large-scale cultivar screening, efforts to understand the genetic architecture of drought tolerance, tools for molecular-assisted drought tolerance improvement, and high-throughput phenotyping capability for efficient cultivar screening. Future research should be devoted to following areas: (1) drought tolerance evaluation to include a broader range of traits, such as root architecture and fruit-related performance under drought stress, to establish stronger association between physiological and molecular signals with drought tolerance mechanisms; (2) large-scale drought tolerance screening across diverse blueberry germplasm to uncover various drought tolerance mechanisms and valuable genetic resources; (3) high-throughput phenotyping tools for drought-related traits to enhance the efficiency and affordability of drought phenotyping; (4) identification of genetic architecture of drought tolerance using various mapping technologies and transcriptome analysis; (5) tools for molecular-assisted breeding for drought tolerance, such as marker-assisted selection and genomic selection, and (6) investigation of the interactions between drought and other stresses such as heat to develop stress resilient genotypes.

Selection of pollution-safe head cabbage: Interaction of multiple heavy metals in soil on bioaccumulation and transfer

Screening for pollution-safe cultivars (PSCs) is a cost-effective strategy for reducing health risks of crops in heavy metal (HM)-contaminated soils. In this study, 13 head cabbages were grown in multi-HMs contaminated soil, and their accumulation characteristics, interaction of HM types, and health risks assessment using Monte Carlo simulation were examined. Results showed that the edible part of head cabbage is susceptible to HM contamination, with 84.62% of varieties polluted. The average bio-concentration ability of HMs in head cabbage was Cd> > Hg > Cr > As>Pb. Among five HMs, Cd and As contributed more to potential health risks (accounting for 20.8%–48.5%). Significant positive correlations were observed between HM accumulation and co-occurring HMs in soil. Genotypic variations in HM accumulation suggested the potential for reducing health risks through crop screening. G7 is a recommended variety for head cabbage cultivation in areas with multiple HM contamination, while G3 could serve as a suitable alternative for heavily Hg-contaminated soils.

Bacterial Leaf Spot Susceptibility Screening of Chili Pepper Cultivars Using qPCR Determination of Xanthomonas euvesicatoria pv. euvesicatoria Titers.

Bacterial leaf spot is a serious disease of chili pepper (Capsicum spp.) caused by Xanthomonas euvesicatoria pv. euvesicatoria. Conventional resistance screening is time and resource intensive. It was considered that a quick and simple determination of cultivar susceptibility could be achieved through estimating bacterial titers of inoculated plants. A SYBR quantitative polymerase chain reaction (qPCR)-based assay was compared with conventional PCR, then used to detect and enumerate pathogen titers in serial dilutions and DNA extracted from infected plant leaves. The qPCR detection limit was approximately 1 CFU µl-1, 10 times more sensitive than conventional PCR. A linear correlation (R2 = 0.994) was obtained from the standard curve comparing plate-truthed serial dilutions of the pathogen with the qPCR cycle threshold. Six strains were used to inoculate cultivars Hugo and Warlock. One strain, X. euvesicatoria pv. euvesicatoria BRIP62403, was consistently the most virulent based on visual symptoms and pathogen titers in planta inferred by qPCR performed on DNA extracted from infected leaves 2 and 6 weeks postinoculation. Visual observations 6 weeks after inoculation were highly correlated (R2= 0.8254) to pathogen titers. The qPCR method was used to categorize 20 chili pepper cultivars 2 weeks after inoculation. A high positive correlation (R2 = 0.6826) was observed between visual scoring and pathogen titers from 20 chili pepper cultivars, facilitating categorization of susceptible, intermediate, and resistant cultivars. The qPCR approach developed here facilitates susceptibility screening of chili pepper cultivars at an early stage of selection and could be readily adapted to a range of other pathosystems.

Screening for Heat and Rain Tolerant Cultivars of Cauliflower for Cultivation in Monsoon Season in the Subtropical Region of Bhutan

There is a shortage of cauliflower in the domestic market during monsoon and early autumn seasons in Bhutan due to the absence of suitable cultivars for cultivation in subtropical region during these seasons. This study was conducted to assess the genotypic variability in yield of different cultivars of cauliflower under heat and rain (flood) stresses in the subtropical region. Four F1 hybrid varieties of cauliflower from the Takii Seeds, Japan (KSB-12.179, KSB-12.180, KSB-18.297 and KSB-20.320) and three F1 hybrid varieties from Syngenta Seeds, India (C-6099, CFL-1522 and Monsoon Queen) were evaluated in August 2022 in open field at ARDC Samtenling. The experiment was laid out in a RCDB design with three replications using Snow Mystique as the check variety. The objective of the study was to identify short duration, rain and heat tolerant varieties of cauliflower for cultivation in the monsoon season (July-August) in the subtropical region of Bhutan. In addition, all the cultivars were further assessed in September, and five cultivars that performed well in monsoon planting were evaluated in November 2022 as the second and third staggered planting trials to find out their performance in late monsoon and main seasons (September-November) respectively. The results from three staggered trials showed that Monsoon Queen matured in 53 days after transplanting (DAT), 56 DAT and 35 DAT in the first, second and third staggered planting trials with the mean head of 462 g, 376 g and 211 g respectively. In comparison, the check variety matured in 142 DAT, 114 DAT and 77 DAT in the first, second and third staggered planting trials with the mean head of 658 g, 403 g and 767 g, respectively. Monsoon Queen was the earliest maturing variety with good head weight and curd quality among the eight cauliflower varieties when transplanted in August 2022. However, both the head yield and curd quality of this cultivar declined in later plantings, indicating that this variety is not suitable for main season (autumn) planting. With the identification of Monsoon Queen as the heat and rain tolerant cultivar in this study, cauliflower can now be grown even in the monsoon season in the subtropical region of Bhutan.

Research status and prospect of ratoon rice in China under mechanically harvested condition.

The proportion and area of ratoon rice planting in China have been substantially increased, due to continuous improvement of rice breeding methods and consecutive innovation of cultivation technology, which has developed into one of rice planting modes with significant production efficiency. Combining the experience in research and practice, from the perspective of crop physiology and ecology, we reviewed the current situation and prospects of high-yielding formation and physiological mechanisms of ratoon rice. We focused on four key aspects: screening and breeding of ratoon rice cultivars and the classification; suitable stubble height for mechanically harvested ratoon rice, as well as water and fertilizer management; dry matter production and allocation in ratoon rice and the relationship with yield formation; regenerative activity and vigor of ratoon rice roots and their relationship with rhizosphere micro-ecological characteristics. As for the extending of mechanized low-cut stubbles ratoon rice technique, we should properly regulate the rhizosphere system, coordinate rhizosphere nutrient supply, germination of axillary buds, and tillering regeneration, to achieve the target of "four-high-one-low", that is high regeneration coefficient, high number of regeneration panicle, high harvest index, high yield, high quality, low-carbon and safe, aiming to improve the sustainability of ratoon rice industry.

Screening of mustard cultivars for phytoremediation of heavy metals contamination in wastewater irrigated soil systems.

The mustard (Brassica juncea L.) plant is a well-known and widely accepted hyper-accumulator of heavy metals. The genetic makeup of mustard's cultivars may significantly impact their phytoremediation capabilities. The present study aimed to investigate the growth performance, yield attributes, and heavy metal accumulation potential of B. juncea cv. Varuna, NRCHB 101, RH 749, Giriraj, and Kranti, cultivated in soil irrigated with wastewater (EPS) and bore-well water (MPS). EPS contributed more Cr, Cd, Cu, Zn, and Ni to tested mustard cultivars than the MPS. EPS reduced morphological, biochemical, physiological, and yield attributes of tested mustard cultivars significantly (p < 0.05) than the MPS. Among the tested cultivars of mustard plants, Varuna had the highest heavy metal load with the lowest harvest index (35.8 and 0.21, respectively). Whereas NRCHB 101 showed the lowest heavy metal load with the highest harvest index (26.9 and 0.43, respectively). The present study suggests that B. juncea cv. Varuna and NRCHB 101 could be used for the phytoextraction of heavy metals and reducing their contamination in food chain, respectively in wastewater irrigated areas of peri-urban India. The outcomes of the present study can also be utilized to develop a management strategy for sustainable agriculture in heavy metal polluted areas resulting from long-term wastewater irrigation.

Exploring genetic divergence and marker-trait associations for leaffolder Cnaphalocrocis medinalis (Guenee) resistance in rice landraces.

Rice production faces a significant threat from the rice leaffolder, Cnaphalocrocis medinalis. To address this challenge, growing resistant varieties stands out as a sustainable and eco-friendly pest management strategy. This necessitates identifying resistant sources and understanding their inheritance patterns through employing DNA markers for marker-assisted resistance breeding. Our study involves screening for resistant cultivars following the SES of IRRI, assessing genetic diversity among landraces using molecular markers, and identifying genomic regions associated with resistance. Screening indicated that 33.33%, 27.08%, 19.79%, and 19.80% of genotypes were resistant, moderately resistant, susceptible, and admixture, respectively. Landraces were categorized into three clusters, with clusters I and II predominantly containing moderately resistant and resistant cultivars, and cluster III mainly susceptible types. Molecular variance analysis revealed 12% variation among populations and 88% within the population. Simple linear regression identified significant marker-trait associations, with markers RM 162 and RM 284 on chromosomes 6 and 8, respectively, found highly associated with leaffolder resistance. Phenotypic variation in leaffolder damage correlated highly with the allelic effects of these markers. Further confirmation of marker linkage with resistance loci was established through independent assays on highly resistant and susceptible genotypes. The information derived from genetic diversity and marker-trait associations will be useful for future marker-assisted resistance breeding programs, enhancing the sustainability of rice production.

Prevalence and Epidemiology of Apple Powdery Mildew in Northwest Himalayan Region of Himachal Pradesh

A survey was conducted to assess the incidence and severity of powdery mildew of apples during April to July of 2020 and 2021 at the different locations of Kinnaur district, Himachal Pradesh, India. Assessment scale of Hofer et al. (2019) with slight modification was used for cultivar screening. Apple seedlings were grown in the pots in the polyhouse of the Department of Plant Pathology in order to test the pathogenicity of Podosphaera leucotricha. Pathogenicity was confirmed through inoculation tests by gently pressing diseased leaves on young leaves of five asymptomatic, potted one-year-old Gale Gala seedlings of apple. Five non-inoculated plants were used for a control treatment. Overall, twenty different apple cultivars were screened against powdery mildew planted under field conditions at Krishi Vigyan Kendra Sharbo, Kinnaur, Himachal Pradesh, India. Out of these cultivars, five cultivars viz. Red Delicious, Royal Delicious, Red Velox, Auvil Early Fuji and Oregon Spur II, were found to be less susceptible to Podosphaera leucotricha, causing powdery mildew of apples, while Granny Smith, Golden Delicious, and Gale Gala were found extremely susceptible. Gala series of cultivars were found to be extremely susceptible to the pathogen. Incidence of the disease ranged from 25.42% to 53.80% and severity from 39.75% to 66.25%, respectively. According to the present study the disease initiated during the first week of May and peaked in the month of July in district Kinnaur. Temperatures between 18–24°C and RH between 50–65% were found to be favourable for the disease development. The conditions in the region were found to favourable for disease development and spread.

Finding stable and closely linked QTLs against spot blotch in different planting dates during the adult stage in barley

The common resistance to Spot Blotch (SB) and drought stress in barley was studied using a RILs population caused Kavir × Badia cross. These lines were inoculated with Cochliobolus sativus Gonbad isolate during the adult stage and were evaluated for three crop seasons in different planting dates. The different osmotic potentials during the flowering were regulated by changing the planting dates. In total, 43 lines had resistant to SB and drought. The high-density linkage map covered 1045 cM of barley genome. A total of five stable and closely linked QTLs to SB resistance were mapped on chromosomes 2H, 3H, 4H and 7H using genome-wide composite interval mapping. Moreover, four stable and closely linked QTLs to SB susceptibility were located on chromosomes 3H, 4H, 5H and 7H. Additionally, the ISJ19-A, SCoT7-C, ISJ17-B, Bmac0144k, iPBS2415-1, Bmac0282b and EBmatc0016 markers can be used for positive screening of resistant cultivars. However, ISJ3-C, UMB310, ISJ9-B, UMB706, D03-D and iPBS2257-A markers can be used for negative screening of susceptible cultivars in marker-assisted selection. The bioinformatics studies showed that QRCsa-2H (ISJ19-A region), QRCsa-2H (SCoT7-C-ISJ17-B region), QRCsa-3H (Bmac0144k region), QRCsa-4H (iPBS2415-1 region) and QRCsa-7H (Bmac0282b-EBmatc0016 region) are involved in the carboxypeptidase, Glycosyltransferase, transcription factors, kinase and AP2/ERF, respectively.

Screening of frost tolerant cultivars of Ber under frost condition

Screening of frost tolerant cultivars of Ber under frost condition

Identification of the Initial Anthesis of Soybean Varieties Based on UAV Multispectral Time-Series Images

Accurate and high-throughput identification of the initial anthesis of soybean varieties is important for the breeding and screening of high-quality soybean cultivars in field trials. The objectives of this study were to identify the initial day of anthesis (IADAS) of soybean varieties based on remote sensing multispectral time-series images acquired by unmanned aerial vehicles (UAVs), and analyze the differences in the initial anthesis of the same soybean varieties between two different climatic regions, Shijiazhuang (SJZ) and Xuzhou (XZ). First, the temporal dynamics of several key crop growth indicators and spectral indices were analyzed to find an effective indicator that favors the identification of IADAS, including leaf area index (LAI), above-ground biomass (AGB), canopy height (CH), normalized-difference vegetation index (NDVI), red edge chlorophyll index (CIred edge), green normalized-difference vegetation index (GNDVI), enhanced vegetation index (EVI), two-band enhanced vegetation index (EVI2) and normalized-difference red-edge index (NDRE). Next, this study compared several functions, like the symmetric gauss function (SGF), asymmetric gauss function (AGF), double logistic function (DLF), and fourier function (FF), for time-series curve fitting, and then estimated the IADAS of soybean varieties with the first-order derivative maximal feature (FDmax) of the CIred edge phenology curves. The relative thresholds of the CIred edge curves were also used to estimate IADAS, in two ways: a single threshold for all of the soybean varieties, and three different relative thresholds for early, middle, and late anthesis varieties, respectively. Finally, this study presented the variations in the IADAS of the same soybean varieties between two different climatic regions and discussed the probable causal factors. The results showed that CIred edge was more suitable for soybean IADAS identification compared with the other investigated indicators because it had no saturation during the whole crop lifespan. Compared with DLF, AGF and FF, SGF provided a better fitting of the CIred edge time-series curves without overfitting problems, although the coefficient of determination (R2) and root mean square error (RMSE) were not the best. The FDmax of the SGF-fitted CIred edge curve (SGF_CIred edge) provided good estimates of the IADAS, with an RMSE and mean average error (MAE) of 3.79 days and 3.00 days, respectively. The SGF-fitted_CIred edge curve can be used to group the soybean varieties into early, middle and late groups. Additionally, the accuracy of the IADAS was improved (RMSE = 3.69 days and MAE = 3.09 days) by using three different relative thresholds (i.e., RT50, RT55, RT60) for the three flowering groups compared to when using a single threshold (RT50). In addition, it was found that the IADAS of the same soybean varieties varied greatly when planted in two different climatic regions due to the genotype–environment interactions. Overall, this study demonstrated that the IADAS of soybean varieties can be identified efficiently and accurately based on UAV remote sensing multispectral time-series data.

Drought-Tolerance Screening of Date Palm Cultivars under Water Stress Conditions in Arid Regions

Drought stress poses a considerable challenge to agriculture sustainability in arid regions. Water scarcity severely affects date palm growth and productivity in these regions. However, as water resources become increasingly scarce in arid regions, understanding the drought tolerance of date palm cultivars becomes imperative for developing drought-resistant cultivars and optimizing irrigation water usage for sustainable agriculture. This research examines the impact of different drought stress levels based on evapotranspiration (ETc), i.e., 40%, 60%, 80%, and 100% ETc, and time intervals (0, 6, 12, 18, and 24 months) on leaf growth, net photosynthesis, chlorophyll a and b content, and leaf relative water content (LRWC) of four prominent date palm cultivars, Khalas, Barhee, Hilali, and Ashrasee. In addition, the study also examines the effects of drought stress on dry weight, potassium and calcium content of leaf, stem, and root, and proline content in fresh leaves of these four cultivars. A solar-powered drip irrigation system with automated time-based irrigation scheduling was used to accurately control the irrigation water amount. To real-time estimate ETc in the study area, meteorological data were collected using a cloud-based IoT system. The findings of this study revealed that severe drought conditions (40 and 60 % ETc) significantly reduced leaf growth, plant dry biomass, and physiological and biochemical attributes; however, date palm cultivars can be grown under moderate drought conditions (80% ETc) with minimal effect on phenotypic, physiological, and biochemical traits to conserve water. The study also revealed that the drought-related characteristics decreased gradually with an increase in water stress time over 24 months. Comparing the date palm cultivars revealed that the Khalas and Barhee cultivars are more drought-tolerant, followed by Hilali, while Ashrasee is susceptible. The study elucidated a water conservation strategy employed in response to drought-induced stress based on the physiological and morphological parameters of date palm cultivars. It provides valuable insights into irrigation practices in arid regions. However, future studies can be focused on other nondestructive innovative techniques such as pulse-amplitude-modulation (PAM) fluorimetry, infrared radiation (IR), and video imaging system (VIS) methods to identify drought stress in date palms.

Screening of new wheat cultivars originating from Kazakhstan for stem and leaf rust resistance genes using PCR markers

Leaf and stem rust that infect wheat lines are the most prevalent and damaging fungal diseases affecting the wheat production rates globally. One of the efficient and economically wise ways of controlling the disease progression is the breeding resistant wheat varieties. Use of molecular markers associated with resistance genes, might be useful for identifying the varieties, that carry the specific resistant genes. Sixty-four wheat cultivars and lines provided by domestic agricultural experimental stations were examined using DNA-markers for the presence of leaf (Lr) and stem (Sr) rust resistance genes. The reactions were carried out using eight pairs of different primers. Six Lr genes (Lr10, Lr13, Lr16, Lr19 and Lr39) responsible for wheat resistance were detected using PCR. The molecular marker detection demonstrated the presence of a combination of several Lr genes, particularly Lr16, Lr34 and Lr39 in the fifteen spring wheat accessions. Six varieties in the nursery of spring soft wheat from KarabAES, two varieties from AktAES (Ekada 113, Lin. 225/21g.) and seven varieties from NorthKazAES (435/Lut 2, 659/12, 486/Lut 22, 23/07, Erith 42/12, 453 SP-2/19) carried the combination these three genes.