Inheritance and molecular mapping of solitary/cluster fruit-bearing habit in Luffa

Fruiting behaviour and sex form are important goals for Luffa breeders and this study aimed to shed light upon inheritance patterns for both these traits. The hermaphrodite form of Luffa acutangula (known as Satputia) is an underutilized vegetable with a unique clustered fruiting habit. Its desirable traits, such as plant architecture, earliness, as well as contrasting traits like unique clustered fruiting, bisexual flower, and crossability with Luffa acutangula (monoecious ridge gourd with solitary fruits), make it a potential source for trait improvement and mapping of desirable traits in Luffa. In the present study, we have elucidated the inheritance pattern of fruiting behaviour in Luffa using F₂ mapping population generated from a cross between Pusa Nutan (Luffa acutangula, monoecious, solitary fruiting) × DSat-116 (Luffa acutangula, hermaphrodite, cluster fruiting). In F₂ generation, the observed distribution of plant phenotypes fitted in the expected ratio of 3:1 (solitary vs cluster) for fruit-bearing habit. This is the first report of monogenic recessive control for cluster fruit-bearing habit in Luffa. Herein, we designate for the first time the gene symbol cl for cluster fruit bearing in Luffa. Linkage analysis revealed that SRAP marker ME10 EM4-280 was linked to the fruiting trait at the distance of 4.6 cM from the Cl locus. In addition, the inheritance pattern of hermaphrodite sex form in Luffa was also studied in the F₂ population of Pusa Nutan × DSat-116 that segregated into 9:3:3:1 ratio (monoecious:andromonoecious:gynoecious:hermaphrodite), suggesting a digenic recessive control of hermaphrodite sex form in Luffa, which was further confirmed by the test cross. The inheritance and identification of molecular marker for cluster fruiting trait provides a basis for breeding in Luffa species.

Harnessing sponge gourd: an alternative source of oil and protein for nutritional security

Luffa cylindrica (L.) Roem. is an important cucurbit crop that assures food security and dietary diversity among the poor communities. In the present study, seeds of 42 genotypes of Luffa cylindrica were evaluated for their potential use as oil seed crop. Seed moisture, oil and protein content and fatty acids profile were estimated along with total phenol and sugar content. Significant differences were observed among the various genotypes where oil content ranged from 15.4-29.8% and protein 19.9-30.8%. Total phenol content was high 6.43-12.84 mg/100 g, which bodes well for the sponge gourd seeds' ability to act as antioxidants. Significant correlation were found between important constituents studied like protein and oil, palmitic acid, stearic acid and oleic acid. Total unsaturated fatty acids were in higher amount comparable to saturated fatty acids signifying the good quality of Luffa seed oil. Our research revealed that the NDSG-1, Pusa Sneha, DSG-95, DSG-98, DSG-108, and DSG-26 genotypes were very nutritious due to their high levels of protein, oleic acid, and oil output. Additionally, selection of traits having considerable correlation will be beneficial and help in improved varietal development for usage as an alternative oilseed crop. Our research sheds light on the nutritional value of sponge gourd seeds and suggests using them as a potential source for oil and protein, particularly in underdeveloped countries.

Sub-surface magma movement inferred from low-frequency seismic events in the off-Nicobar region, Andaman Sea

Monitoring volcanic activity along the submarine volcanoes that are usually induced by subsurface magmatism is a challenge. We present fresh set of Ocean Bottom Seismometer (OBS) data that shows geophysical evidence indicative of subsurface magmatism along the submarine volcanoes in the off Nicobar region, Andaman Sea. In this region, we observed for the first time, hybrid very long-period earthquakes documented by passive OBS experiment. These events were initiated by high-frequency (5-10 Hz) with a clear onset of P-phase followed by low-frequency (0.01-0.5 Hz) oscillations in the range of 300-600 s with a prominent high-frequency (10-40 Hz) hydro-acoustic phase. A total of 141 high-frequency events were detected on 21st and 22nd March 2014 out of which 71 were of low-frequency oscillations. These events are distributed in the northwest-southeast direction along the submarine volcanic arc and Seulimeum strand of Great Sumatra fault. Off Nicobar region has been witnessing frequent earthquake swarms since 26th December 2004 tsunamigenic Sumatra earthquake. These swarms occurred in January 2005, March and October 2014, November 2015 and March 2019. The occurrence of low-frequency earthquakes and prominent hydro-acoustic phase are suggestive of sub-surface tectonic and magmatic influence. We propose that upward movement of magma pulses from deeper magma reservoir to the shallow magma chamber activated the strike-slip movement of sliver faults and induced earthquake swarms in the off Nicobar region.

Genetic diversity and population structure detection in sponge gourd (Luffa cylindrica) using ISSR, SCoT and morphological markers

Investigation of genetic diversity is essential for the selection of parents for crop breeding and conservation of genetic resources. To estimate the genetic variability and population structure in the midst of 45 accessions of sponge gourd brought together from different geographical areas of India, morphological traits and two molecular markers, ISSR and SCoT markers were compared. Principal components analysis of 20 morphological traits showed 72.70% variability and significant positive correlations between fruit traits. All three marker techniques clustered all accessions into two groups with few outgroups. High level of polymorphism was observed among ISSR (74.6%) and SCoT (71.5%) primers. The Bayesian model revealed the hidden grouping and showed admixture type of population. The diversity pattern is influenced by genetic marker used, as different molecular markers have different polymorphism evaluation efficiency. This study can be helpful in amplifying the genetic base and selection of specific traits for breeding. Thus, ISSR and SCoT markers are potential marker for identification in sponge gourd and provide valuable data on its genetic correlation and structure.

Transferability of cucumber microsatellite markers used for phylogenetic analysis and population structure study in bottle gourd (Lagenaria siceraria (Mol.) Standl.)

Improved breeding for developing fruit quality in bottle gourd (Lagenaria siceraria (Mol.) Standl.) necessitates knowledge regarding its genetic diversity. To achieve this, a set of 108 locus-specific SSR markers has been developed in bottle gourd by cross-species transferability from 995 mapped Cucumis sativus SSR markers. During screening, 280 primer pairs amplified in the bottle gourd germplasm, which were further evaluated in a diverse set of 42 lines, resulting in 19 polymorphic, 89 monomorphic, 15 with multiple bands, and the rest 157 showed no or very non-specific amplification. The 19 polymorphic primer pairs produced a total of 54 alleles. Gene diversity, Shannon's information index, and Nei's coefficient of differentiation were calculated suggesting a moderate genetic variation at the species level. A model-based population structure analysis divided these germplasm into two subpopulations. This marker set will be applicable for evaluating the genetic structure for association mapping, DNA fingerprinting, and mounting linkage maps and will be a practical tool set for further genetics. This study provides one of the first quantitative views of population genetic variation in bottle gourd.

DPPrimer - A Degenerate PCR Primer Design Tool

Designed degenerate primers unlike conventional primers are superior in matching and amplification of large number of genes, from related gene families. DPPrimer tool was designed to predict primers for PCR amplification of homologous gene from related or diverse plant species. The key features of this tool include platform independence and user friendliness in primer design. Embedded features such as search for functional domains, similarity score selection and phylogebetic tree further enhance the user friendliness of DPPrimer tool. Performance of DPPrimer tool was evaluated by successful PCR amplification of ADP-glucose phosphorylase genes from wheat, barley and rice.

Ellis-van Creveld Syndrome: a report of two cases

Ellis-van Creveld syndrome (EVC) or chondroectodermal dysplasia, a rare autosomal recessive disorder, is a tetrad of chondrodysplasia, ectodermal dysplasia, polydactyly, and congenital heart disease, of which chondrodystrophy of the tubular bones is the most common feature, while central nervous system (CNS) and urinary tract anomalies are some of its rarer associations. This report describes EVC syndrome in two sisters of Indian origin, ages 8 and 6 years, the products of nonrelated, unaffected parents. The patients had chondrodysplasia of tubular bones resulting in disproportionate dwarfism, polydactyly, severely dystrophic nails, partially absent teeth, and short and bound-down upper lips with multiple frenulae. Other features noted in the girls were syndactyly and mild mitral regurgitation. All four of the classic features of EVC syndrome were present in patient 1 and three in patient 2. Additional findings were ichthyosis and plantar keratoderma in the former and absent clavicles in the latter, which have not been reported previously. The importance of prenatal diagnosis of EVC is stressed and a multidisciplinary approach for the management of these patients is highlighted.

Linear and whorled nevoid hypermelanosis

Linear and whorled nevoid hypermelanosis (LWNHM) is a reticulate pigmentary disorder with a sporadic occurrence, representing genetic mosaicism. It is characterised by hyperpigmented macules in a reticulate pattern along Blaschko's lines, sparing the mucous membranes and stabilising after one to two years. It may be associated with various neurological abnormalities. The disorder may resemble incontinentia pigmenti, epidermal nevus, or zebra-like hyperpigmentation clinically. We report LWMNHM in a 15-year-old girl with progressively increasing streaks of reticulate hyperpigmented macules arranged in a whorled pattern over the trunk and extremities, which appeared soon after birth. There was no history of any preceding eruption or any associated systemic abnormality. Histopathological examination revealed basal cell hyperpigmentation without any pigmentary incontinence. CT scan of the brain was normal.

Cutaneous tuberculosis in children a clinico-microbiological study

Twenty untreated patients of cutaneous tuberculosis varying from 2-12 years of age were included in the study. The incidence of cutaneous tuberculosis amongst the paediatric dermatological patients was 0.36%. Of these, 10 had lupus vulgaris, 8 had scrofuloderma, 3 had tuberculosis verrucosa cutis and 2 had lichen scrofulosorum. Three patients concomitantly had more than one type of skin tuberculosis. Systemic involvement in the form of pulmonary and osseous system was seen in 45% cases. The tuberculin test was uniformly positive. Affirmative clinico-histopathological correlation was observed in all the patients. However, acid fast bacilli could not be demonstrated in any of the sections. Only one patient (scrofuloderma) exhibited AFB on smear examination. In the same patient, M. tuberculosis could be cultured on L-J medium. However, Elisa for IgM antibodies in serum was positive in 12 (60%) cases. Need for newer techniques in the diagnosis is emphasised.