Onion Genotypes Research Articles

Genetic analysis of fertility restoration systems and cytoplasmic types in onion (Allium cepa) genotypes using DNA markers

Genetic analysis of fertility restoration systems and cytoplasmic types in onion (Allium cepa) genotypes using DNA markers

Genetic characterization of white onion genotypes (Allium cepa L.) using ISSR markers

Understanding the genetic characteristics is crucial for preserving and developing Moroccan's white onion genotypes, with increased yield and quality as well as improved tolerance to biotic and abiotic stresses. In the present paper, inter simple sequence repeat (ISSR) markers were used to assess the genetic diversity and characteristics of white onion genotypes (Allium cepa L.) of Morocco. Based on the ISSR markers bands, 28 white onion genotypes were divided into four distinguished subgroups, with a genetic similarity value of 0.46 based on Jaccard index. Molecular markers analysis revealed that all ISSR markers were 100 % polymorphic with the white onions genotypes. Concerning markers performance, polymorphic information content (PIC) ranges from 0.051 to 0.39 with a mean of 0.301; however, the effective multiplex ratio (EMR) and marker index (MI) vary between 3–17 and 0.35–5.04, respectively. Based on resolving power (RP), it appears that the marker UBC825 has an efficient discriminatory power with an RP = 15.67. In contrast, the lowest RP value was detected with the marker UBC815 (RP = 1.58). Based on their high performance, markers UBC825, UBC835, UBC826, UBC840, and UBC811 ISSR seem to be specific and efficient for the identification of Moroccan white onion genotypes. Thus, given the genetic diversity shown by ISSR markers, the abundant resources of white onion genotypes in Morocco could be exploited in more valuable ways.

Marker assisted selection of male sterile (CMS-S) lines among short day Indian onion genotypes

Marker assisted selection of male sterile (CMS-S) lines among short day Indian onion genotypes

Effects of Genotypes and Mulching on Growth and Yield of Onion

Selection of the right genotype and optimizing management practices are essential for higher crop productivity. In the area of onion cultivation, the correlation between onion genotypes and mulching remains a relatively unexplored terrain. To identify this association, an experiment was conducted at the Horticulture Development Resource Centre, Kaski, from November to April 2023. Structured in two factorial randomized complete block designs, the experiment featured five genotypes—AVON 1052, AVON 1103, Khumal 1, Khumal 2, and Red Creole (check variety)—and two mulching levels, namely black plastic mulch and control, with four replications. Significant variations were found among genotypes in response to mulching. Red Creole, Khumal 1, and AVON 1103 exhibited a significant difference in plant height and leaf number. AVON 1052, Khumal 2, and Khumal 1 showed a substantial divergence in average total bulb diameter with and without mulching. Furthermore, with the exception of Red Creole, other genotypes demonstrated a significant difference in total bulb yield, favoring mulching with black plastic. Khumal 2, produced a yield of 11.7 t ha-1 without mulching, attributed its success to larger bulb diameter, more leaves (8), and taller plants (66.8 cm), while Khumal 2 (16 t ha-1) under mulching showed similar yielding potential as Red Creole. Ultimately, the recommendation of mulching in Khumal 2 was given owing to the bulb-splitting problem in Red Creole and indifferent yield in Khumal 2 as compared to Red Creole. This research shows how better onion types and using mulch can enhance onion production and promote agricultural sustainability in Nepal.

Assessing onion genotypes stability and potential in diverse Indian environments

Assessing onion genotypes stability and potential in diverse Indian environments

A comparative biochemical characterization of Allium genetic resources of Türkiye

AbstractThe present study aimed to determine the variation in onion and garlic genetic resources collected from the Kelkit Valley, a unique biodiversity concerved region in Türkiye. For this purpose, 17 onion genotypes and 12 garlic genotypes were collected from local growers. A total of 9 biochemical analyses (total phenolic matter, total soluble protein, total dry matter, total flavonoid matter, ferric reducing antioxidant power, cupric reducing antioxidant capacity, 2,2-diphenyl-1-picrylhydrazylradical scavenging activity, hydrogen peroxide scavenging capacity and ascorbic acid) were performed on bulb and leaf extracts of all genotypes. According to variance analysis of the biochemical results from the samples, the differences between genotypes for all parameters were found to be significant (p < 0.05). A post-hoc test (Tukey) and multiple means comparison were performed to analyze the results between groups in cases of significant differences. The results indicated that there is a large variation between different genotypes of both species and between both species and organs.

Screening of Onion (Allium cepa L.) Genotypes for High Yield Potential in Mid Hills Region of Himachal Pradesh

Onion (Allium cepa L.) is one of the most important bulbous vegetable crops, belongs to the family Amaryllidaceae. Thirty genotypes were taken under study. Sufficient significant variation was observed among all the genotypes for all the characters under study. The maximum plant height was seen in the genotype UHF-ONI-13 (69.08 cm) while, minimum in the genotype UHF-ONI-7 (34.15 cm). Highest polar diameter and equatorial were represented by the genotype UHF-ONI-13 (5.59 cm) and Bhima Kiran (5.99 cm), respectively. There were nine genotypes which exhibited globular shape, three showed torpedo shape and eighteen showed flat shape. The majority, comprising 18 genotypes, exhibited a dark red color for their bulb skinThe genotype recorded to have earliest 50 per cent neck fall was UHF-ONI-4 (129.67 days). Maximum bulb weight was recorded by the genotype UHF-ONI-13 (82.95 g). Bulb yield per plot and per hectare was observed maximum in UHF-ONI-13 (8.19 kg and 436.86 q). UHF-ONI-13, UHF-ONI-15 and UHF-ONI-16 performed better than other genotypes for yield and other imperative horticultural characters. Thus, these genotypes can be used for further breeding improvement programmes of onion for different traits.

Exploring sequence-related amplified polymorphism (SRAP) markers for assessing genetic diversity in onion (Allium cepa L.) genotypes and their wild relatives

Exploring sequence-related amplified polymorphism (SRAP) markers for assessing genetic diversity in onion (Allium cepa L.) genotypes and their wild relatives

Evaluation of Onion (Allium cepa L.) Genotypes for Yield and its Attributes Traits under Bundelkhand Region of Uttar Pradesh, India

The present investigation was conducted at the Vegetable Research farm at the College of Horticulture, Banda University of Agriculture and Technology, Banda, Uttar Pradesh, during the Rabi season 2019-2020. The experiment was conducted in randomized block design with 20 genotypes of onion. The result obtained showed that the NHRDF Red-4 is performing the best among all genotypes in characters viz., plant height at 75 DAT, number of leaves per plant at 75 DAT, equatorial bulb diameter, 20 bulb weight, average bulb weight, gross yield kg per plot, gross yield q/ha, marketable yield kg/plot and marketable yield q/ha. The Bhima Shweta performed superior regarding most of the traits viz., double (%) on number basis, bolters percentage on number basis, rotten percentage at number basis, days to maturity at 60-70% neck fall, days to harvesting after transplanting, thrips per plant and TSS percentage but the genotype/variety Sukh Sagar took minimum duration and mature only in 80 days after transplanting, it is harvested before others genotypes/varieties and also yielded well, so this variety can be also recommended for cultivation in Uttar Pradesh.

Influence of genetic and environmental factors on incidence of bolting in short day onions

Bolting is the premature flowering malady in bulb crop of onion cultivation. It has detrimental effects on bulb quality and market value. This research aimed to investigate the relationship between genetic predisposition and environmental conditions in relation to bolting in different onion genotypes and hybrids. Findings revealed that, the divergent patterns between the regions of Bengaluru and Bagalkot indicate that weather differences in geographical locations play a significant role in influencing the bolting tendencies of onions. The rabi season exhibited the highest bolting rate (15.09%), surpassing the kharif (0.21%) and summer (1.53%) seasons, emphasizing the role of seasonality in triggering bolting. Interestingly, even under identical environmental conditions, yellow onions demonstrated higher bolting percentage compared to red and white onions, suggesting the presence of genetic variation. This variation could be attributed to disparities in the presence and expression levels of the bolting genes. Collectively, these results highlight the combined influence of genetic and environmental factors, as well as their interactions on onion bolting tendencies.

Onion (Allium cepa L.) and Drought: Current Situation and Perspectives.

Onions (Allium cepa L.) are the second most commonly produced and consumed vegetable worldwide due to their economic, nutritional, and medicinal benefits. However, drought hinders vegetative growth, lowers yields and bulb quality, reduces photosynthetic activity, and alters the onion plant's metabolism. This review provides a summary of global research on the impact of drought on onions. It specifically seeks to shed light on aspects that remain unclear and generate research avenues. Relevant scientific articles were sourced from the AGORA database, Web of Science (WoS), and search engines such as Google Scholar, Scopus, MEDLINE/PubMed, and SCImago to achieve this objective. A total of 117 scientific articles and documents related to onion and drought were critically examined. The review revealed agromorphological, physiological, biochemical, and genomic studies depicting factors that contribute to drought tolerance in onion genotypes. However, there was little research on the physiological, biochemical, and genetic characteristics of drought tolerance in onions, which need to be deepened to establish its adaptation mechanisms. Understanding the mechanisms of onion response to water stress will contribute to fast-tracking the development of drought-tolerant genotypes and optimize onion production. Future research should be more focused on investigating onion drought tolerance mechanisms and structural and functional genomics and identifying genes responsible for onion drought tolerance.

Genetic variability appraisal and inter-relationships between different quantitative and qualitative traits in diverse late kharif onion (Allium cepa L.) genotypes

Genetic variability appraisal and inter-relationships between different quantitative and qualitative traits in diverse late kharif onion (Allium cepa L.) genotypes

Post-harvest Storage Losses Study in Onion Genotypes

The study was conducted at Vegetable Research Farm, Department of Horticulture, Bihar Agricultural University, Sabour, Bhagalpur during Rabi season 2021-22 with the objective to study the storage losses in various varieties of onion and identify those varieties with a good storage life. The experimental material consisted of 15 onion genotypes from different locations in India. Observations on physiological loss in weight, rotting and sprouting percentage were recorded at fortnight level upto 90 days. Variety and storage time had significant effect on weight loss, sprouting and rotting. Overall, during the three months of storage period, minimum physiological loss in weight was observed in LC-1 (5.80%) which was statistically at par with LC-2 (6.05%), Patna Red (6.20%), Bhima Shakti (6.21%), Agrifound Light Red (6.54%) and NHRDF local (6.83%). The minimum rotting was observed in LC-1 (13.32%) which was statistically at par with LC-2 (14.73%). Sprouting was not observed throughout the storage period in any of the genotypes. LC-1, LC-2, Patna Red and Bhima Shakti had good storage as compared to other genotypes. These genotypes can be explored in the breeding programmes for production of high yielding varieties with good storage potential.

Assessment of genetic diversity and stability performance of 38 genotypes of onion (Allium cepa L.)

ABSTRACT The current study was conducted at four different locations in India in order to evaluate the genetic diversity and stability of 38 genotypes of onion (Allium cepa L.) under various climatic circumstances. The genetic diversity was evaluated through cluster analysis which divided thirty-eight genotypes into two major clusters (cluster I and cluster II) each of which had 20 and 18 genotypes. As per Additive Main-effects and Multiplicative Interaction (AMMI) model, five genotypes from cluster I, namely Accession (Acc.) 1217, 1209, Bhima Shweta, 1639, and 1640 were shown to have greater adaptation, with regressive values of 0.14, 0.74, 1.51, 2.11, and 2.17, respectively and marketable yields ranging from 176.23–227.31 q/ha. The mean performance of genotypes in individual clusters revealed that the cluster I and cluster II genotypes showed maximum marketable yield, total yield and average bulb weight. Based on the findings of the assessment study, these stable genotypes could be utilised as parent plants in future breeding programmes to develop high-yielding onion varieties that not only showcase stability but also possess widespread adaptability, thereby enhancing overall onion crop performance.

Yield potential of onion genotypes in the Planicie Huasteca, Mexico

Objective: To identify new generation onion genotypes with high yield per unit that meet the bulb quality characteristics required by the export market.
 Design/Methodology/Approach: Eight onion hybrids with yellow bulb, six hybrids with white bulb, and three hybrids with purple bulb were evaluated. The experiments were established with drip irrigation and fertigation. The agronomic characteristics of the plant and the production and quality of the bulb were evaluated, using the USDA specifications for bulb width and shape. The experiments were carried out using a completely randomized block design, with three replications; the statistical analysis was performed using the SAS software, version 9.2.
 Results: The best onion genetic materials for the Planicie Huasteca were the yellow bulb hybrids Wayne and Don Víctor, the white bulb hybrids Blanca Grande, Monja Blanca, and Don Alberto, and the purple bulb hybrid Rasta, all of which have high production capacity and bulb quality.
 Study Limitations/Implications: Onion (Allium cepa L.) is the most extensive horticultural crop in the Planicie Huasteca, Mexico. Although regional producers establish outstanding genotypes, they require information about the new generation genetic materials, if they are to remain competitive in the export market. Therefore, the new genotypes with the best high yield potential and bulb quality must be evaluated to select those that meet the requirements of the market.
 Findings/Conclusions: Yellow, white, and purple bulb onion genotypes with high production capacity that meet the requirements of the markets were identified.

Studies on genetic variability and heritability in bulb onion (Allium cepa L.) in the South-Eastern plains of Bihar, India

The study was conducted at Vegetable Research Farm, Department of Horticulture, Bihar Agricultural University, Sabour, Bhagalpur during Rabi season 2021-22 with the objective to study genetic variability in onion (Allium cepa L.) for yield and yield attributing traits. The experimental material consisted of 15 onion genotypes from different locations in India. Experimental trial was laid out in a RBD with three replications. Analysis of variance was done by the method suggested by Panse and Sukhatme (1967). The observations were recorded on five randomly selected plants of all genotypes for plant height, number of leaves, leaf length, leaf width, pseudostem length, neck thickness, polar diameter, equatorial diameter, and average bulb weight. Analysis of variance indicated significant differences among the genotypes for all the characters under study which implied a considerable amount of genetic variability in the genotypes included in the study. The highest average weight of onion bulb was recorded in genotype LC-1 (62.13g) which was statistically at par with LC-2 (58.53g), Patna Red (57.80g), Bhima Shakti (57.28 g) and Agrifound Light Red (56.87g). High PCV and GCV were recorded for pseudostem length and neck thickness. Moderate GCV and PCV were found in leaf width, average bulb weight, plant height, leaf length, equatorial diameter and bulb size index. High heritability along with high genetic advance as percentage of mean was exhibited by all the morphological traits. The genotypes LC-1, LC-2, Patna Red and Bhima Shakti were identified as promising ones for the yield and yield contributing traits.

Comparative assessment of onion seed longevity under ambient storage and artificial ageing conditions

A study was carried out to assess the storage potential of onion genotypes under natural as well as accelerated ageing conditions. Freshly harveted seeds of thirty onion genotypes were subjected to nine months of natural ageing as well as accelerated ageing for 3 and 6 days (42oC and 75% RH). Significant effects of seed ageing on germination percent, seed vigour index, mean germination time and germination index were recorded. Germination percent ranged from 56.0- 96.0 percent in unaged seeds, which declined to 31.0-82.0 and 18.0-83.0 percent respectively after natural (9 months) and accelerated ageing treatments (6 days). In the current study, the seed germination and vigour indices decreased significantly, whereas the mean germination time increased for all the genotypes under both ageing treatments. Further, cluster analysis was utilized to categorize the onion genotypes into good or poorer storers. A significant and positive correlation was found among both natural as well as artificial ageing treatments. The study facilitated the categorization of onion genotypes into distinct storage groups by evaluating their performance under both natural as well as accelerated ageing.

AcCNGC2, coding a cyclic nucleotide-gated channel protein from onion, enhances Phytophthora nicotianae resistance in transgenic Nicotiana benthamiana

The cyclic nucleotide-gated channel (CNGC) proteins encode Ca2+ cation channels, which play vital roles in plant biotic and abiotic stress responses. Phytophthora nicotianae has a wide range of host plants and causes severe damage to a wide range of crops including onion (Allium cepa L). Here, an AcCNGC2 gene was isolated from onion based on the transcriptome analysis. AcCNGC2 showed higher expression in resistant onion genotype L17136 compared to susceptible line F419025. AcCNGC2 was a plasma membrane-localized protein and contained conserved regions of plant CNGC protein, such as transmembrane domains and the cyclic nucleotide-binding domain. The transcripts of AcCNGC2 were induced by CaCl2, salicylic acid, H2O2, and cAMP. AcCNGC2 ectopic overexpression in Nicotiana benthamiana lines presented milder disease symptoms than that of wild type (WT) after P. nicotianae inoculation. After inoculation with P.nicotianae, the concentration of Ca2+ and the expression of the NbCAM gene were significantly increased in AcCNGC2 overexpression lines. The overexpression of AcCNGC2 promoted the accumulation of reactive oxygen species (ROS) and upregulated the NbRBOHD transcript level. In addition, AcCNGC2 overexpression promoted the expression of NbCDPK and NbPR1, which related to the pathogen resistance. Moreover, AcCNGC2 interacted with itself to form a calcium channel participating in plant disease resistance. The results indicated that AcCNGC2 played a positive role in P.nicotianae resistance by regulating Ca2+ and ROS accumulation and downstream resistance-related genes expression.

Reactions of Short, Intermediate and Long Day Onion Genotypes in Turkish National Onion Breeding Program to Fusarium Basal Rot Disease

Onion basal rot (Fusarium oxysporum f. sp. cepae) disease exerts serious threats on global onion (Allium cepa L.) production and trade. Present breeding programs mostly focus on development of cultivars resistant to onion basal rot disease. Characterization of breeding material in breeding gene pool is the first step of breeding. This study was conducted to determine the susceptibility of 4 onion cultivars, 30 long-day, 1 intermediate-day and 21 short-day onion genotypes to onion basal rot disease. Significant differences were seen in disease susceptibility of the genotypes (P<0.01 ) in both onion seedling and bulb tests. Onion seedling and bulb tests revealed that resistance was not detected in short and intermediate-day onion genotypes and cultivars, while two of long-day onion genotypes (ACLD 7 and 8) were found to be tolerant. Based on present finding, 3 cultivars, 28 long-day, 1 intermediate-day and 21 short-day genotypes were identified as sensitive. ACLD 7 and 8 long-day onion genotypes, which were identified as promising in seedling tests, were also identified as tolerant in bulb tests and such findings proved the compliance of seedling and bulb tests. Bulbs were obtained from the long-day onion lines (ACLD 7-8 genotypes) that were found to be promising and survived in seedling tests and seeds were obtained from these genotypes to ensure progress of generation and they were included in breeding gene pool.

Overexpression of AcCDPK1 and AcCDPK5 from Allium cepa. L enhances Phytophthora nicotianae resistance in Nicotiana benthamiana

The Ca2+-dependent protein kinases (CDPKs) play important roles in Ca2+ signal transduction pathway in plant biotic stress response. In this study, AcCDPK1 and AcCDPK5 were isolated from onion. AcCDPK1 and AcCDPK5 showed higher expression in Phytophthora nicotianae resistant onion genotype compared to the susceptible onion line. AcCDPK1 and AcCDPK5 were cell membrane-localized proteins and contained conserved regions of plant CDPK protein, such as a serine‑ threonine protein kinase domain and a C-terminal calmodulin-like domain. AcCDPK1 and AcCDPK5 ectopic overexpression in Nicotiana benthamiana presented milder disease symptoms than that of wild type after P. nicotianae inoculation. The overexpression of AcCDPK1 and AcCDPK5 promoted the accumulation of ROS and upregulated the NbRBOHD transcript level at the initial stage of inoculation. In addition, AcCDPK1 and AcCDPK5 overexpression promoted the expression of NbPR1, which was related to the pathogen resistance. AcCDPK1 performed more obvious roles than AcCDPK5 in P. nicotianae resistance. The results suggested that AcCDPK1 and AcCDPK5 played a positive role in P. nicotianae resistance by regulating ROS accumulation and downstream resistance related genes expression.