"Transferability of SSR markers has been reported in several crop families, such as Moraceae,Rosaceae, Rutaceae, Myrtaceae, Juglandaceae, Anacardiaceae and Poaceae etc. [20 - 26].Released SSR sequences in the model Cucumis sativus genome via whole genome sequencinghave been transferred across species in various crops of Cucurbitaceae, such as pumpkin (C.maxima), watermelon (Citrullus lanatus) and gherkin (Cucumis anguria L.), with amplification% of SSR in melon, pumpkin and watermelon are 48.9%, 22.2% and 25.9%, respectively [27],but till date, there is a dearth of SSR markers in bottle gourd. With this knowledge, we attemptedto utilize the benefit of these SSR markers to gauge the genetic variability of bottle gourd.Herein, these markers were used to assess genetic diversity in 2 different bottle gourdpopulations from northeast and northern region of India, consisting of 42 germplasm to facilitatemore efficient parental line selection and to trace the genetic admixture underlying eachgermplasm. Therefore, the main objectives of the present study were to: (i) assess the transferability ofCucumis sativus SSR markers to bottle gourd; (ii) evaluate polymorphism of the transferableSSR markers in bottle gourd; and (iii) test efficiency of the transferred SSRs for genetic structureand diversity analyses of bottle gourd. Transferability of Cucumber derived SSR markers to L.siceraria The positive amplification of cucumber SSR markers in bottle gourd indicates thetransferability between these two cucurbit species. Of the 995 primer pairs, 280 showed bright bands when they were screened with two controlbottle gourd germplasm, indicating a successful transferability of the cucumber SSR markers.But while profiling with 280 cucumber-derived primer pairs, only 108 were producing intenseand clear amplification product with 42 lines of bottle gourd, thus these primers were defined astransferable. Transferability of successful SSR markers to Lagenaria siceraria is shown in Table 2. Not all SSR markers produced the similar sized product in L. siceraria as the cucumbercontrols. The PCR bands of SSR23757 and SSR12258 were relatively faint in L. siceraria thoughthe annealing temperature was lowered from 55°C to 53?C, which seems to be suitable for bottlegourd. Some primers among the studied 995 transferable cucumber SSR markers showedmultiple bands when amplified in L. siceraria for a single cucumber SSR marker, e.g. SSR11654.Some primers produced stutter bands in L. siceraria, need more standardization of PCRprogram. Most of the cucumber SSR markers CM16 could amplify DNA fragments only in some of L.siceraria germplasm, indicating that the cross-species transferability of cucumber SSR markersshows the germplasm-dependent result. 108 primer set among 280 produced intense and brightbands in a complete set of L siceraria germplasm. These markers have importance for geneticanalyses of L. siceraria and are novel markers in the species. Sequence confirmation and PIC ofthe transferred SSRs markers For confirmation of SSR in the amplified polymorphic loci, five L.siceraria bands of variable size from two different markers were randomly selected, amplifiedfragment were gel extracted and sequenced to scan whether SSR motifs were present in amplifiedfragments. The same SSR motif and but different repeat numbers were observed in L. siceraria for theallelic bands of SSR21663 and SSR22874 (Fig. 2A and 2B), and the SSR sequence identitieswere more than 90% between L. siceraria and cucumber. But the allelic sequence length of PCRamplicon in L. siceraria was not fully consistent with that in cucumber, indicating variationoccurred between the two species. Therefore, PCR-based transferability of cucumber SSRmarkers to L. siceraria does not necessarily mean that the sequences in bottle gourd areidentical to that in the target site of cucumber genome. Polymorphic information content (PIC) defines a relative measure of the informativeness of a marker, or discriminatory power of apolymorphic marker which depends on the number of alleles and relative frequency of an allelein the population. The 19 transferable polymorphic cucumber-derived SSR markers gave rise tototal 54 discernible polymorphic DNA fragments. As shown in Table 3, PIC values varied from0.01 to 0.54 with a mean of 0.33 for the 19 transferable SSR markers (Fig. 3). The binaryscoring data from the 19 polymorphic primers (Fig. 4 showing an example of polymorphicprimer) were subjected to NTSYS-pc 2.01 software, for constructing UPGMA dendrogram basedon the Jaccards similarity coefficient and is presented in Fig. 5, UPGMA based dendrogramdoes not show correlation with the geographical locations. Jaccard’s coefficient of similarityvalues (GS) ranged from 0.11 to 0.75, with a mean of 0.41 among the 42 germplasm. The smallest similarity value (0.11) suggested the high divergence between BG12 and BG57 andthe maximum similarity value (0.75) was scored between samples BG5 and BG45. Thedendrogram for 42 bottle gourd germplasm revealed three main clusters; Cluster I was thelargest, comprising 19 germplasm, cluster II comprised of 17 germplasm and cluster III was verysmall consisting of 5 germplasm only, which were also divided into numbers of sub-clusters. Incluster III one cultivar BG12 was present as an outgroup, the most diverse germplasm. Population structure: The population structure of the bottle gourd germplasm was inferredusing Structure 2.3.4 software based on the 57 SSR markers. One population contained 19germplasm, among which 12 were from the northern India. Seven germplasm from the north- eastern region were also grouped in this population. The second population contained 23 germplasm, 16 from the north India and 7 germplasm from the north-eastern region. A narrowgenetic base has been reported for bottle gourd [1], probably because repeated use of the sameparents with good fruit quality in breeding causing considerable genetic erosion of the bottlegourd gene pool. Future breeding must concentrate on using a wider range of germplasm forbottle gourd improvement. "