Genetic analysis of bioactive compounds and antioxidant properties in lettuce (Lactuca sativa)

Leaves of lettuce (Lactuca sativa L.) are the store house of various phytonutrients which have protective properties. Being an important dietary leafy vegetable, it is primarily consumed fresh as salad and in sandwiches, burgers etc. Its beneficial effects are primarily due to the presence of different phytochemicals such as ascorbic acid, carotenoids, polyphenols and fibre which helps in protecting key biological constituents such as lipoproteins, membranes and DNA. However, systematic biochemical nutrient analysis has not been carried out in this important salad vegetable so far. In the present investigation, 36 genotypes were analysed for phytochemicals such as total carotenoids, lycopene, ascorbic acid, total phenolic content, Cupric ion Reducing Antioxidant Capacity (CUPRAC) and Ferric Reducing Antioxidant Power (FRAP). The CUPRAC ranged from 0.05 to 1.98 μmol trolox/g with the highest content in Stem lettuce Angustana, whereas FRAP ranged from 0.06 to 4.70 μmol trolox/g showing, thereby, a considerable variation amongst genotypes. Total phenolics ranged from 41.94 to 501.88 μg gallic acid/g fresh weight. Total carotenoids were found in appreciable amount in Wo Suen (46.13 mg/100g fresh weight), whereas lycopene in New Chicken (17.01 mg/100g fresh weight). Ascorbic content ranged from 1.14 to 3.75 mg/100g fresh weight, whereas per cent moisture ranged from 86.50 (NVRS 10:001818) to 97.32 (Sheetal). Positive correlation was observed between total carotenoids and lycopene, chlorophyll b with chlorophyll a, total chlorophyll with both chlorophyll a and b, FRAP with CUPRAC and phenols with total chlorophyll, chlorophyll a and b. Maximum phenotypic and genotypic coefficients of variance were calculated for FRAP (165.98, 165.98) followed by CUPRAC (122.10,122.10) and lycopene content (83.33, 80.84), respectively. These genotypes can be further utilized for development of multinutrient rich varieties. Regular consumption of lettuce can go a long way in tackling osteoporosis, anemia, and cardiovascular related problems

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Not AvailableLettuce is considered as a high value vegetable due to its richness in phytonutrients. Nowadays, it is produced all the year round and consumed fresh so that all the ingredients stay intact. Estimation of different elements in different types of lettuce is essential in developing nutritionally rich, good quality varieties for cultivation. Sixty two genotypes comprising both heading and non-heading types were analyzed for six mineral content such as Calcium, Sulphur, Zinc, Copper, Manganese and Iron. The genotypes studied belonged to six lettuce types, namely Latin (three), Stem (five), Crisphead (thirteen) Butterhead (Eight), Leaf (twenty three) and Cos (ten). Overall, latin types were rich in sulphur, while crisphead types were rich in calcium and copper and butterhead in zinc, manganese and iron. The stem types, however, were found to be lesser in most of the minerals compared to other types. The Pennlake Crisphead lettuce genotype had highest calcium content (390.07 ppm), New chicken stem type had highest sulphur content (7.80 ppm), L-S-2 leaf type had highest zinc content (29.91 ppm), Balmoral crisphead type had highest copper content (10.98 ppm), Great takes Katrain crisphead type had highest magnesium content (44.94 ppm) followed by Sheetal crisphead type (44.11 ppm) and All source butterhead type had highest iron content (605.52 ppm). The comprehensive analysis helped by providing detailed information about the composition of minerals of different types as well as genotypes. The information so obtained will go a long way in developing mineral content dense lettuce varieties.Not Availabl

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Not AvailableLettuce is considered as a high value vegetable due to its richness in phytonutrients. Nowadays, it is produced all the year round and consumed fresh so that all the ingredients stay intact. Estimation of different elements in different types of lettuce is essential in developing nutritionally rich, good quality varieties for cultivation. Sixty two genotypes comprising both heading and non-heading types were analyzed for six mineral content such as Calcium, Sulphur, Zinc, Copper, Manganese and Iron. The genotypes studied belonged to six lettuce types, namely Latin (three), Stem (five), Crisphead (thirteen) Butterhead (Eight), Leaf (twenty three) and Cos (ten). Overall, latin types were rich in sulphur, while crisphead types were rich in calcium and copper and butterhead in zinc, manganese and iron. The stem types, however, were found to be lesser in most of the minerals compared to other types. The Pennlake Crisphead lettuce genotype had highest calcium content (390.07 ppm), New chicken stem type had highest sulphur content (7.80 ppm), L-S-2 leaf type had highest zinc content (29.91 ppm), Balmoral crisphead type had highest copper content (10.98 ppm), Great takes Katrain crisphead type had highest magnesium content (44.94 ppm) followed by Sheetal crisphead type (44.11 ppm) and All source butterhead type had highest iron content (605.52 ppm). The comprehensive analysis helped by providing detailed information about the composition of minerals of different types as well as genotypes. The information so obtained will go a long way in developing mineral content dense lettuce varieties.Not Availabl

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Not AvailableIn January 2012, lettuce (Lactuca sativa L.) plants (19 out of 38) of one of the accessions (EC687345, variety NVRS-10:001818) exhibiting mild mosaic and stunted growth symptoms were observed at the Indian Agricultural Research Institute (IARI) experimental farm, New Delhi. Similar disease symptoms in lettuce plants in India were previously described (3) and the associated virus was characterized for host range, dilution end point, thermal inactivation point, and longevity in vitro. In this study, definitive molecular evidence is presented for the presence of Lettuce mosaic virus (LMV) infecting lettuce in India. Analysis of preparations from leaves of symptomatic samples with an electron microscope revealed flexuous virus particles measuring 750 × 13 nm, suggesting the association of a potyvirus (4). To identify the potyvirus infecting these lettuce plants, the 3′ terminal portion of the genome including the part of the nuclear inclusion b (NIb), complete coat protein (CP) region, and 3′ untranslated region (UTR) was amplified by RT-PCR, cloned, and sequenced. Total RNA was extracted from infected leaves using an RNeasy Plant Mini Kit (Qiagen, Valencia, CA) and subjected to RT-PCR using potyvirus specific forward (5′ ACCACAGGATCCGGBAAYAAYAGYGGDCARCC 3′) and reverse (5′ CACGGATCCCGGG(T17)V 3′) primers (2). PCR products (~1.8 kb) were cloned into pGEM-T Easy vector (Promega, Madison, WI) and sequenced (GenBank Accession No. JQ794776). Sequence comparisons revealed the CP of the virus infecting lettuce (834 bp) shared 96 to 100% nucleotide and deduced amino acid sequence identity with the corresponding regions of LMV isolates AJ306288 and AJ297630 from the United Kingdom, CAA46603 and NC003605 from the United States, AJ278854 and AJ278854 from Brazil, and AJ488153 from China, thus complying with the cut off range of 90 to 99% for identifying isolates/strains of the same virus (1). Similarly, 99 to 100% nucleotide sequence identity was observed with the corresponding region of the 3′UTR (245 bp) while 93 to 96% nucleotide identity of NIb region (654 bp) with LMV isolates. These results confirm that the virus infecting the symptomatic lettuce plants was an isolate of LMV. The amino acid sequences (DAG and WCIEN) conserved among majority of potyviruses were also present. Since the virus is aphid transmissible, its natural infection on other hosts and spread can't be ruled out.Not Availabl

Conservation and Dispersion of Genes Conferring Resistance to Tomato Begomoviruses between Tomato and Pepper Genomes

In the present climate change scenario, controlling plant disease through exploitation of host plant resistance could contribute toward the sustainable crop production and global food security. In this respect, the identification of new sources of resistance and utilization of genetic diversity within the species may help in the generation of cultivars with improved disease resistance. Begomoviruses namely, Tomato yellow leaf curl virus (TYLCV) and Chilli leaf curl virus (ChLCV) are known to cause major yield losses in several economically important crop plants of the family Solanaceae. Though co-occurrence, association and synergistic interactions among these viruses in the host plants is reported, whether orthologous genetic loci in related host plants could be responsible for conferring resistance to these viruses has not been investigated yet. Several loci including Ty1, Ty2, Ty3, Ty4, and ty5 have been reported to confer resistance to leaf curl viruses in tomato. Here, we examined the pepper orthologous markers, corresponding to these QTL regions, for polymorphism between ChLCV susceptible and resistant genotypes of pepper. Further, to examine if the polymorphic markers are segregating with the disease resistance, Bulk Segregant Analysis (BSA) was performed on F2 population derived from crosses between resistant and susceptible lines. However, none of the markers showed polymorphism in BSA suggesting that the tested markers are not linked to genes/QTLs responsible for conferring resistance to ChLCV in the selected genotypes. In silico analysis was performed to study the synteny and collinearity of genes located within these QTL regions in tomato and pepper genomes, which revealed that more than 60% genes located in Ty2 and Ty4, 13.71% genes in Ty1, 23.07% in Ty3, and 44.77% genes located within ty5 QTL region in tomato are conserved in pepper genome. However, despite such a high conservation in gene content, the linkage relationship in these regions seems to be greatly affected by gross rearrangements in both the species

Introgression of Black Rot Resistance from Brassica carinata to Cauliflower (Brassica oleracea botrytis Group) through Embryo Rescue

Black rot caused by Xanthomonas campestris pv. campestris (Xcc) is a very important disease of cauliflower (Brassica oleracea botrytis group) resulting into 10–50% yield losses every year. Since there is a dearth of availability of resistance to black rot disease in B. oleracea (C genome), therefore exploration of A and B genomes was inevitable as they have been reported to be potential reservoirs of gene(s) for resistance to black rot. To utilize these sources, interspecific hybrid and backcross progeny (B1) were generated between cauliflower “Pusa Sharad” and Ethiopian mustard “NPC-9” employing in vitro embryo rescue technique. Direct ovule culture method was better than siliqua culture under different temperature regime periods. Hybridity testing of F1 inter-specific plants was carried out using co-dominant SSR marker and Brassica B and C genome-specific (DB and DC) primers. Meiosis in the di-genomic (BCC) interspecific hybrid of B. oleracea botrytis group (2n = 18, CC) × B. carinata (2n = 4x = 34, BBCC) was higly disorganized and cytological analysis of pollen mother cells revealed chromosomes 2n = 26 at metaphase-I. Fertile giant pollen grain formation was observed frequently in interspecific F1 hybrid and BC1 plants. The F1 inter-specific plants were found to be resistant to Xcc race 1. Segregation distortion was observed in BC1 generation for black rot resistance and different morphological traits. The At1g70610 marker analysis confirmed successful introgression of black rot resistance in interspecific BC1 population. This effort will go a long way in pyramiding gene(s) for resistance against black rot in Cole crops, especially cauliflower and cabbage for developing durable resistance, thus minimize dependency on bactericides

Genetics and Molecular Mapping of Black Rot Resistance Locus Xca1bc on Chromosome B-7 in Ethiopian Mustard (Brassica carinata A. Braun).

Black rot caused by Xanthomonas campestris pv. campestris (Pam.) Dowson is the most destructive disease of cauliflower causing huge loss to the farmers throughout the world. Since there are limited sources of resistance to black rot in B. oleracea (C genome Brassica), exploration of A and B genomes of Brassica was planned as these were thought to be potential reservoirs of black rot resistance gene(s). In our search for new gene(s) for black rot resistance, F2 mapping population was developed in Brassica carinata (BBCC) by crossing NPC-17, a susceptible genotype with NPC-9, a resistant genotype. Out of 364 Intron length polymorphic markers and microsatellite primers used in this study, 41 distinguished the parental lines. However, resistant and susceptible bulks could be distinguished by three markers At1g70610, SSR Na14-G02 and At1g71865 which were used for genotyping of F2 mapping population. These markers were placed along the resistance gene, according to order, covering a distance of 36.30 cM. Intron length polymorphic markers At1g70610 and At1g71865 were found to be linked to black rot resistance locus (Xca1bc) at 6.2 and 12.8 cM distance, respectively. This is the first report of identification of markers linked to Xca1bc locus in Brassica carinata on B-7 linkage group. Intron length polymorphic markers provided a novel and attractive option for marker assisted selection due to high cross transferability and cost effectiveness for marker assisted alien gene introgression into cauliflower

Map of R locus (<i>Xca1bc</i>) conferring resistance to <i>Xanthomonas campestris</i> pv. <i>campestris Xcc</i> race 1.

<p>Marker and R locus (<i>Xca1bc</i>) are depicted on the right side of the estimated map and the distances are on the left. This linkage group corresponds to LG 7 of B genome of <i>Brassica carinata</i>.</p

Phenotypic evaluation of resistant and susceptible parental genotypes and F₂ population (NPC-17 × NPC-9) of <i>Brassica carinata</i> against <i>Xanthomonas</i> pv. <i>campestris</i> race 1.

<p>(a) Susceptible genotype ‘NPC-17’ (b) resistant genotype ‘NPC-9’, (c) leaves showing black rot disease resistance reaction in segregating F₂ mapping population and (d-f) susceptible disease reaction in segregating F₂ mapping population.</p

Molecular markers linked to R gene conferring resistance to <i>Xcc</i> race 1 in <i>B</i>. <i>carinata</i>.

<p>Molecular markers linked to R gene conferring resistance to <i>Xcc</i> race 1 in <i>B</i>. <i>carinata</i>.</p