Onion Genotypes Research Articles

Responses of Allium cepa L. exposed to silver nanoparticles

The study was aimed to determine the gallic acid, rutin and quercetin contents and yield of Narli onion genotype (Allium cepa L.,) exposed to four different doses (0, 25, 50, 75, 100 mg L-1) of silver nanoparticles (AgNPs)for30 days, after planting the onion bulbs, attwo-week intervals. Quercetin, rutinand gallic acid contents in the leaves and bulbs of onion plants were determined.While the quercetin content was the highest in 25 mg L-1ofAgNPs treatment (575.0 ± 10.39 µg g-1)in the bulb parts, gallic acid content reachedtothe highest rate in 50 mg L-1 of AgNPs(3605.8 ± 90.96µg g-1), inthe onion bulb, compared to the control (2819.3 ± 65.72µg g-1).The content of rutinwere enhanced in 25 (19.72 ± 0.28µg g-1), 50 (21.66 ± 0.57µg g-1) and 75 mg L-1(31.08 ± 0.53 µg g-1) of AgNPs treatments, but it was significantly close to the control (7.15 ± 0.93µg g-1), in100 mg L-1(10.92 ± 0.38 µg g-1), in bulb parts.Chlorophyll content showed reducesin all doses, except for25 mg L-1 of AgNPs treatment. Total yield enhanced in treatments of AgNPs, but the highest increase was obtained in treatment of 50 mg L-1 of AgNPs (97.49 ± 0.92 µg g-1). The analysis of quercetin, rutin and gallic acid contents were performed by high performance liquid chromatography (HPLC), and Chlorophyll was determined by SPAD.

Development of polyclonal antibodies using bacterially expressed recombinant coat protein for the detection of Onion yellow dwarf virus (OYDV) and identification of virus free onion genotypes

Onion yellow dwarf virus (OYDV) belonging to the genus Potyvirus, family Potyviridae, is one of the widely distributed viruses of Allium species worldwide. It causes dwarfing, yellow striping, crinkling and flaccidity of the leaves of onion and garlic. To see the occurrence and incidence of OYDV on Allium crop, an attempt was made to develop antibody based diagnostic assay which would be useful for routine indexing and screening of the germplasm. The total RNA was isolated from the symptomatic leaves of onion and the gene encoding coat protein (CP) was cloned. The nucleotide sequencing analysis of the cloned RT-PCR product revealed ~ 774bp amplicon (OYDV CP) and it was further cloned in pET-28a ( +) expression vector which yielded ~ 30kDa fusion protein with Histidine tag (His6BP). The expression of fusion CP was primarily checked on SDS-PAGE and further confirmed by Western blot. The His6BP-OYDV-CP was obtained in soluble state after purification and was used to immunize New Zealand white rabbit for the production of polyclonal antibody (PAb). The produced PAb against the purified fusion protein successfully detected OYDV from onion and garlic samples at 1:2000 dilutions in indirect-enzyme linked immunosorbent assay (DAC-ELISA). Thus, this study presents first report that Histidine tag (His6BP) fusion OYDV-CP based antibody production and its successful application in identification of virus free onion and garlic genotypes.

English

A field experiment entitled, “Evaluation of rabi onion genotypes for storage characteristics (six month period)” was conducted during rabi season, 2017-18 at “Scheme for Research on Onion Storage”, Department of Horticulture, Mahatma Phule Krishi Vidyapeeth, Rahuri. Dist. Ahmednagar (Maharashtra) India. The experiment was carried out in Randomized Block Design with seventeen genotypes and one check variety i.e. N-2-4-1 treatments replicated three times. In storage studies results indicated that, the minimum storage losses (Sprouting losses (%), Rotting losses (%), PLW losses (%) & Total losses) were recorded by the genotypes T7, T11 and T10.The minimum sprouting losses (after 6 month storage) was recorded in genotype T11 (1.41 %). It was followed by genotype viz. T7 and T10 (1.51 %). The maximum sprouting losses (after 6 month storage) was recorded in genotype T17 (4.06 %). Rotting losses (after 6 month storage) ranged between T11 (3.19) to T4 (7.46) per cent. The minimum PLW loss was recorded in genotype T7 (14.98 %), followed by genotype viz. T11 (15.64 %), T10 (15.85 %) and T6 (17.16 %). The maximum PLW loss was recorded in genotype T17 (33.26 %). The minimum total losses (after 6-month storage) was recorded by genotype T11 (21.34 %). While the maximum total losses (after 6-month storage) was recorded in T4 (36.49 %). Considering the above results, it could be concluded that, among the seventeen genotypes T7 (RHROR–7), T10 (RHROR–10) and T11 (RHROR–11) found promising for further evaluation.

Variability and genetic diversity among selfed lines (S1) of onion (Allium cepa L.)

Onion is a highly cross-pollinated crop, high variability could possibly come from traditional seed production by out-crossing or by open pollination and it could lead to more diversity and variation. The high phenotypic, genotypic variation coefficients reveal high-quantifiable variation of traits in S1 lines. Selection of lowest premature bolting and split bulbs producing genotypes, least incidence of purple blotch incidence and thrips incidence with the highest weight of ten bulbs and maximum plot yielding genotypes were more appropriate for genetic improvement of onion. The traits aided the yield witnessed high traits heritability (h2) and maximum genetic-advance-mean (GAM) and isolation of S1 lines in terms of selection indices fixed for higher values of measurement. Whereas traits like premature bolting, split bulbs, purple blotch incidence, thrips incidence and were selected at least values although these traits were high heritability (h2) and GAM could contribute for additive-gene-action and hence it indicates the straight mass selection be more effective for genetic improvement of onion genotypes or lines. The genetic distance was highly flanked by Cluster-II and –IV groups and was highly divergent. Hence, the selection of parental lines from these groups is more appropriate for traditional heterosis breeding.

Low pungency and phytochemicals relationship during bulb assessment in the sweet onion breeding program

This work reports the results of a four-year Italian breeding program carried out over five locations, for the selection of low pungency onion genotypes. The performances of new Italian open-pollinated (OP) lines were compared to both pungent and non-pungent commercial varieties. Pungency level was evaluated on each single bulb as pyruvic acid concentration, together with other related quality traits, namely soluble sugars (SSR), total phenols (TPC) and flavonols (TFC). All OP lines were classified as low to medium pungent onions, and only the lines 09/12, 14/12 and 15/12 slightly exceeded the limit of 3 mmol/kg for the low pungency. In the first two years of selection, OP lines showed a general decrease in pyruvic acid concentration (from 16 to 67%) in the second year, while on average SSR did not significantly change and phenolics increased. SSR appeared positively correlated with pyruvic acid concentration, TPC and TFC. A marked effect of the environmental conditions was observed over the different years and locations of experiment. Overall, 13/12 OP line distinguished for the highest reduction of pyruvic concentration, which averaged 3.0 mmol/kg, while maintaining a high level of SSR (6.6 °Brix), TPC and TFC (1.78 and 0.49 mM gallic and rutin equivalents, respectively).

Competition of onion genotypes in the soil and climatic conditions of Guarapuava, State of Paraná

The use of genotypes more adapted to climatic conditions can contribute to increase the yield of onion producers. The goal of this study was to evaluate the agronomic performance of 15 onion genotypes in the soil and climatic conditions of Guarapuava, state of Paraná. The study was conducted in the experimental area of Horticulture, Cedeteg campus, Universidade Estadual do Centro-Oeste (UNICENTRO), Guarapuava, state of Paraná, Brazil, from July to November 2018. The experimental design used was randomized blocks, with four replications, and the treatments consisted of four commercial cultivars Optima F1, Bella Dura, Sirius F1, Soberana F1 and eleven experimental genotypes N1, N2, N3, N4, N5, N6, N7, N8, N9, AF4241 and AF4243. Biometric characteristics of the plants, production components and early flowering were evaluated. Plants presented between 6 and 9 leaves, in which N1, N3, N4 and N6 had less than 7 leaves, differing statistically from the others. The cultivar Optima F1 and the genotypes N2, N3, N5, N6, N7 and N8 presented the tallest plants, with 66.1 to 76.0 cm. The pseudostem diameter did not differ significantly between genotypes, showing values between 15.2 and 20.4 mm. Total productivity was higher in genotypes N2, N6, N5, N4, N3, N7 with values from 43.6 to 50.3 t ha-1. The highest average bulb mass was found in N2, N4, N6, Sirius F1, Optima F1 and Soberana F1, with 74.2 to 91.1 g bulb-1. Regarding the commercial classification, the genotypes N2, N4, N5, N6 and the cultivars Sirius F1 and Soberana F1 presented more than 50% bulbs of classes 3+3C+4. Early flowering did not occur in any of the analyzed genotypes. The use of cultivars with high productive performance and adapted to climatic conditions, when handled properly, can result in greater yield and quality of bulbs.

Agronomic performance and physicochemical characteristics of onion genotypes under different spacing in the humid Amazonian tropics

The Southwest region of Pará state, Brazil, imports 100% of all onion consumed from other regions of the country, which generates market dependence and raises the product's costs. The present study investigated parameters related to germination, agronomic performance and postharvest characteristics of five onion cultivars at different planting densities. The experiment was conducted in two stages. In the first, in a greenhouse, the germination kinetics was evaluated. In the second, in the field, the seedlings were transplanted into beds. The experimental design was in complete randomized blocks in a 5 x 3 factorial scheme with three replications. The treatments consisted of the combination of five cultivars (Mata Hari, Dulciana, Cimarron, NUN 1205-F1 and Vale Ouro IPA 11) and three line spacing (20, 30 and 40 cm) 8 cm between plants. As for the germination rate (GR), the results allowed to highlight the cvs. Cimarron and Vale Ouro IPA 11 with an 80.55% and 77.77% of GR, respectively. There was a significant difference for total bulb productivity, highlighting Vale Ouro IPA 11 in the 8 x 20 cm spacing. For the bulb diameter, cv. Vale Ouro IPA 11 obtained the best results in all classes. In the average weight of the bulbs, cv. Vale Ouro IPA 11 in the 8 x 40 cm spacing was the best treatment with 60.77g. As for total soluble solids, cv. Vale Ouro IPA 11 presented °Brix higher than the others, being significant at 1%. These results demonstrate that it is possible to produce quality onions in the Southwest region of Pará, which would reduce prices, since all commercialized onions come from regions outside the state.

In Vitro Regeneration of Onion (Allium cepa L.) Genotypes under Salt Stress Condition

Salinity is a major problem affecting crop production all over the world. Excessive soil salinity can reduce the productivity of many agricultural crops including many vegetables and spices. Onion is one of the most important spices in the Asiatic region which is now in high demand. The experiment was conducted to observe in vitro regeneration of onion (Allium cepa L.) under salt stress condition from September 2016 to July 2017. The experiment was conducted as two factorial (genotype and treatment) Completely Randomized Design (CRD) with 3 replications for each treatment. Shoot tip segments of three genotypes namely Faridpuri, Taherpuri and Pusa red (Indian) were cultured in MS (Murashige and skoog, 1962) media supplemented with 25, 50, 75 and 100 mM NaCl. The genotype Faridpuri gave maximum salt tolerance upto 100 mM salinity level with 10.60 cm shoot length and 1.94 cm root length having the highest relative shoot and root growth. Pusa red was found to be salinity sensitive genotype which showing lowest shoot length of 7.03 cm and root length of 0.96 cm at 100 mM NaCl treatment. However, Taherpuri was tolerant up to 100 mM salinity level with 8.14 cm shoot length and 1.25 cm root length. Both the highest fresh weight of root (54.77 mg) and dry weight of root (41.36 mg) was from the genotype Faridpuri with 25 mM NaCl treatment. However, a convenient in vitro regeneration protocol of onion genotypes under different salinity level has been developed and the genotype Faridpuri can be used for further investigation in field condition to evaluate its performance at various salinity levels.

Screening of Onion (Allium cepa L.) Genotypes for Drought Tolerance Using Physiological and Yield Based Indices Through Multivariate Analysis.

Drought is a leading abiotic constraints for onion production globally. Breeding by using unique genetic resources for drought tolerance is a vital mitigation strategy. With a total of 100 onion genotypes were screened for drought tolerance using multivariate analysis. The experiment was conducted in a controlled rainout shelter for 2 years 2017–2018 and 2018–2019 in a randomized block design with three replications and two treatments (control and drought stress). The plant was exposed to drought stress during the bulb development stage (i.e., 50–75 days after transplanting). The genotypes were screened on the basis of the drought tolerance efficiency (DTE), percent bulb yield reduction, and results of multivariate analysis viz. hierarchical cluster analysis by Ward’s method, discriminate analysis and principal component analysis. The analysis of variance indicated significant differences among the tested genotypes and treatments for all the parameters studied, viz. phenotypic, physiological, biochemical, and yield attributes. Bulb yield was strongly positively correlated with membrane stability index (MSI), relative water content (RWC), total chlorophyll content, antioxidant enzyme activity, and leaf area under drought stress. The genotypes were categorized into five groups namely, highly tolerant, tolerant, intermediate, sensitive, and highly sensitive based on genetic distance. Under drought conditions, clusters II and IV contained highly tolerant and highly sensitive genotypes, respectively. Tolerant genotypes, viz. Acc. 1656, Acc. 1658, W-009, and W-085, had higher DTE (>90%), fewer yield losses (<20%), and performed superiorly for different traits under drought stress. Acc. 1627 and Acc. 1639 were found to be highly drought-sensitive genotypes, with more than 70% yield loss. In biplot, the tolerant genotypes (Acc. 1656, Acc. 1658, W-085, W-009, W-397, W-396, W-414, and W-448) were positively associated with bulb yield, DTE, RWC, MSI, leaf area, and antioxidant enzyme activity under drought stress. The study thus identified tolerant genotypes with favorable adaptive traits that may be useful in onion breeding program for drought tolerance.

Genetic variability studies for yield and yield contributing traits in onion (Allium cepa L.)

The onion (Allium cepa L.) bulb productivity is influenced by genotypes and seasonal environmental conditions. The selection of diverse genotypes with high variability is highly desirable, along with the extent of heritability and genetic advance of genotypes for wide adoption and cultivation. The present investigation was carried out by collecting genotypes from the onion growers. The results revealed that the variance of onion genotypes characters ranged from 2.87 to 43.56% for the genotypic coefficient of variation, 3.65 to 46.24% for the phenotypic coefficient of variation. Traits with higher genotypic coefficients of variation and phenotypic coefficients of variation indicated the existence of variation of traits among genotypes and lines. Heritability ranged from 24.72 to 96.85% and genetic advance mean ranged from 2.94 to 84.55%. Higher heritability and genetic advance mean to indicate the presence of additive gene action, thereby indicating that simple mass selection would be more reliable to improve traits in onion. The degree of association, the genotypic correlation was greater than the phenotypic correlation among onion genotypes. The yield was highly significant and was, correlated with growth and yield attributing traits among genotypes. Plot yield was influenced by direct and indirect positive, and negative, effects of growth, quality and yield attributing traits. Direct mass selection of desirable traits would be effective for bulb yield improvement in onion.

Identification of stability and productivity the local red onion Palu based on the effect of genotype and planting location using a Structural Equation Model (SEM)

The effort to find superior varieties is initially by regarding the genotype and location because of these factors contribute to the significance of the interaction between genotype and location (GEI) on productivity. This study is important in plant breeding because the results can be used to predict and to select the genotypes that are stable and adaptable at different planting location. Paying attention to productivity is not sufficient in the GEI analysis to select superior varieties. As a result, a method such as Structural Equation Model (SEM) is needed to explain the effect of genotype and environmental factors on GEI. The obtained results based on the AMMI biplot showed that the genotypes of red onion which have stable productivity at five planting locations, namely Batu (G1) and Sanren F1 (G4). Furthermore, the genotype that is stable planted in five locations is Kawak (G7). The SEM output showed that physical characteristics affect the number of productivity. However, environmental factors such as altitude, soil physical and acid contribute to the productivity of the plant. Finally, we can conclude that the genotypes planted in low locations with soil pH greater than 6 and dusty loam soil conditions will provide more product of red onion with good quality.

Evaluation of different onion genotypes for quantitative and qualitative characters under central part of Uttar Pradesh

Twenty-one genotypes were evaluated for quantitative and qualitative characters of onion crop was carried out during rabi season of the year 2019-20 at Vegetable Research Farm, Department of Vegetable Science, Chandra Shekhar Azad University of Agriculture and Technology, Kalyanpur; Kanpur. The experiment was laid out in randomised complete block design with three replications. The experimental material consisting of twenty-one genotypes of onion maintained at the DOGR Nasik Maharashtra were utilized. Among genotypes evaluated OC 18-75 performed better for most of the characters like plant height (56.8 cm), polar bulb diameter (6.4 cm), total yield (279.75 q/ha), marketable yield (270.75 q/ha) and C-grade bulb (38.8%). Genotype OC 18-91 recorded maximum number of leaves (9.2 cm), OC 18-68 showed maximum equatorial diameter (6.4 cm) and OC 18-89 highest TSS (13.06%).

Studies on genetic variability and divergence in onion (Allium cepa L.)

A study on variability, heritability, genetic advance and genetic divergence between traits in fifty three diverse onion genotypes was carried out for bulb yield, yield attributing traits and quality parameters. The range of variation was maximum for average bulb weight followed by leaf area, total soluble solids and yield per plot. The genotypic coefficient of variation (GCV) was high for average bulb weight (16.09%) followed by yield per plot (13.06%), total soluble solids (11.94%), leaf area (11.75%) and leaf area index (11.75%). The phenotypic coefficient of variation (PCV) was high for average bulb weight (16.90%) followed by leaf area (16.41%), leaf area index (16.41%), yield per plot (13.70%) and total soluble solids (12.77%). Higher heritability estimates along with high genetic advance as per cent of mean (GAM) was observed for yield per plot followed by average bulb weight and total soluble solids. All fifty three genotypes were grouped into ten different clusters. The highest inter cluster distance was observed between cluster IV and X (204.78) and lowest between cluster I and V (35.56).Based on cluster means the important cluster was cluster IX for plant height, bulb neck thickness, number of rings cluster X for leaf area, leaf area index, average bulb weight, total soluble solids, bulb length and yield per plot cluster VIII for number of leaves cluster V for bulb diameter and cluster VII for bulb shape index. Accordingly, parents could be selected for hybridization. The highest intra cluster distance was observed between cluster VII (40.09). The high diversity found in the genotypes showed its great potential for improving qualitative as well as quantitative traits in onion.

Evaluation of rabi onion genotypes for morphological and biochemical characters

Evaluation of rabi onion genotypes for morphological and biochemical characters

Physiological Responses of Gamma-Irradiated Onion Bulbs during Storage

The present study aimed to evaluate the effects of different doses of gamma radiation on some physiological characters of onion genotypes and the expression of PAL gene in the best interaction of gamma irradiation dose and onion genotype treatment. To this aim, four onion genotypes (White-Qom, White-Neyshabour, Red-Ridge- Lump, and Red-Ray-Corrugated) irradiated at 0, 30, 60, 90, 120, and 150 Gy. After four months of storage (at 10-15 °C and 70% relative humidity), the effects of gamma rays on the dry matter (DM), protein content, phenylalanine ammonia lyase (PAL) and peroxidase (POD) were investigated. In addition, the expression of PAL gene in the best interaction of gamma irradiation dose and onion genotype treatment was assessed. The result indicated that POD activity was increased by most of the gamma irradiation levels; however, the protein content and PAL activity were decreased. Moreover, dry matter content was found to be highly genotype-dependent. A linear regression (R2= 0.82) between PAL activity and gamma irradiation levels, was observed. PAL activity decreased with increasing in gamma irradiation level, while the expression rate of PAL gene was not significantly changed between irradiated and non-irradiated control, indicating that the radiation might not have direct effects on the gene regulatory elements. These results suggest that gamma irradiation could reduce the PAL activity possibly by controlling abiotic stress sources such as fungal and bacterial stresses.

Evaluation of onion genotypes to slippery skin caused by Burkholderia gladioli pv. Alliicola

ABSTRACT Onion’s (Allium cepa) slippery skin caused by Burkholderia gladioli pv. alliicola is one of the bacterial diseases that stand out in producing regions of the Brazilian Northeast. Given the importance and potential threat of this disease, and the absence of resistant varieties, the aim of this study was to evaluate the reaction of onion genotypes to slippery skin and to analyze the tolerance stability of the most promising genotypes to different strains of the bacteria. Nine strains of B. gladioli pv. alliicola were artificially inoculated in onion bulbs cv. Baia Periforme and the three most aggressive strains (CCRMBG39, CCRMBG172 and CCRMBG212) were selected to evaluate the tolerance to the disease. Fifty-eight onion genotypes were challenged with the most aggressive strain (CCRMBG39) and 34 genotypes were considered as tolerant, with a disease severity varying from 9.79 to 13.42 mm. The fifteen most promising genotypes and the most susceptible genotype were selected to study the stability of tolerance using the three selected strains. The genotypes F2 (EHCEB 20151030 x EHCEB 20133015), Cascuda T5, Crioula Mercosul, Juporanga, EHCEB 20111036, Cascuda T6 and EHCEB 20142028 remained tolerant to the disease when inoculated with the three strains, with a disease severity ranging from 9.13 to 14.19 mm. In view of these results, we conclude that these genotypes can be used as potential sources of tolerance to onion slippery skin.

Evaluation of Physico-Chemical Composition in Bulbs of Red, Yellow, and White Onion (Allium Cepa L.) Genotypes of Sub-Tropical India

In this study, thirty onion (Allium cepa L.) genotypes grown in sub-tropical region of India were analysed for different physico-chemical attributes. There were significant differences among genotypes, and the onion genotypes showed a tendency to be classified according to different colours. The cultivars of the same colour exhibited similar tendencies in terms of accumulating most of the analysed components. About 1.78 fold variation in dry matter (%) and 2 fold variation in fresh weight per bulb were recorded among coloured onions. Red genotype D-888-B possessed maximum contents of TS and NRS, while the yellow coloured genotype POH-5 accumulated highest RS and lowest NRS contents. Maximum values of fructans (3.68 g/100 g DW), AIS (6 g/100 g DW), protein (10.61 g/100 g DW), and FAA (4.24 g/100 g DW) were also found in red coloured genotypes D-715-B, D-97-B, PR-305, and D-PS-121-B, respectively. Proline content in different genotypes was found to vary about 6.9 fold. The correlation studies showed a positive relationship between most of the quality parameters. Our results suggested that red group genotypes were better than yellow and white groups for all the studied parameters except for RS, which makes red genotypes more suitable for processing purposes.

Evaluation of onion (Allium cepa L.) genotypes for growth and yield parameters under eastern dry zone of Karnataka

A field experiment was conducted to know the performance of onion (Allium cepa L.) genotypes in Eastern Dry Zone of Karnataka during 2015-16 at College of Horticulture, Kolar, Karnataka. Twenty five genotypes (13 varieties, 10 hybrids and 2 synthetics) were collected and evaluated in Rabi season. The research work was carried out to identify the elite genotypes suitable for Rabi season cultivation for higher bulb yield. The performance of the different genotypes with respect to growth and bulb yield were studied. The hybrid Flare (38.50 t/ha), Super Flare (37.00 t/ha) and S-780 (36.40 t/ha) were found best for obtaining quality bulb yield. In the studies, onion F1 hybrids were found to be superior to the synthetics and open pollinated varieties for higher bulb yield. Therefore, it is concluded that onion F1 hybrids need to be popularise for commercial cultivation for increasing productivity in the country.

Identification and characterization of white onion (Allium cepa L.) genotypes for high total soluble solid content through molecular markers

Onion (Allium cepa L.) is one of the most important bulbous vegetable used in global kitchen. Although it has various important traits but among them the high total soluble solid content (HTSS) of white onion is highly preferred by the industries for processing purpose. Looking into the broader use of the white onion; we utilized a total of 23 polymorphic simple sequence repeats (SSRs) and intron length polymorphic markers (ILPs) to characterize thirty five white onion genotypes for HTSS. Further, we also correlated these DNA fingerprint data with the TSS for identification of HTSS and LTSS lines. The total average numbers of alleles for SSR and ILP locus, heterozygosity (He) and polymorphism information content were found to be 2.4, 0.35 and 0.29 respectively. The UPGMA dendrogram revealed two distinct clusters of genotypes. Based on the TSS and DNA genotype data, our study revealed that Bhima-shweta (LTSS-12.09%, sub-cluster IAa) & WHT-12L-HT-15-Reject-M-7(HTSS- 18.02%, cluster II) are more diverse than the others. Other white onion lines including WHTB-7G-GT-15-SC-M-7 small bulb (HTSS 18.80%), WHT-2B-GT-18-SC-M-7 (HTSS 18.51%), WHTS-4D-GT-18-MC-M-7 (HTSS 18.49%), WHTB-3C-GT-18-MC-M-7 (HTSS 18.27%) and WHTS-11K-Pickle-SC-M-7 (HTSS 17.68%) were identified as superior HTSS lines. These identified diverse HTSS and LTSS lines could be useful for the mapping of HTSS coding genes for the acceleration of molecular breeding of onion through the marker assisted selection (MAS) which could be used by the industries for the larger scale processing of the white onion products required by the global community.

Study of genetic divergence in kharif onion cultivars

Twenty-two diverse onion genotypes were evaluated to study the genetic divergence in kharif onion during Kharif season at C-block farm, BCKV, Kalyani, Nadia, West Bengal. All the genotypes were clustered into three groups based on Mahalanobis D2 statistic. Cluster I comprised of accessions with highest yield, yield related traits and TSS. Cluster II was composed of accessions having highest Total sugar, dry matter, pyruvic acid and phenol content. Cluster III was the largest cluster comprising of accessions having highest polar diameter, neck thickness, days to maturity, bolters and ascorbic acid content. Both total yield and marketable yield together explained almost 85 percent contribution of diversity, whereas the contribution of other traits were only 15 percent.