Survey on biodiversity and conservation of indigenous jujube germplasm This study was conducted at five unions (Shreerampur, Angaria, Muradia, Lebukhali and Pangasia) of Dumki Upazila in Patuakhali district, Bangladesh during January 2016-February 2017. It is located between 22°23′-22°30′ north latitude and 90°17′- 90°27′ east longitudes. Data were collected randomly by visiting 70 homesteads of 5 unions where total population was 210 considering 3 plants in each homestead from that population 42 samples were taken for this study as promising germplasm. The respondents from homesteads were interviewed with pre-formulated questionnaire. Each germplasm was conserved in the homesteads in In-situ condition with GPS and passport data.
Characterization and categorization of promising germplasm Germplasm of jujube (Ziziphus jujuba) were tagged and randomly one branch was selected in each direction (North, South, East and West) to collect field data from each plant. The field experiment was conducted in Randomized Complete Block Design (RCBD) with four replications and the laboratory experiment was done in Completely Randomized Design (CRD) with three replications. To evaluate each Jujube germplasm, six different morphological traits viz; fruit weight, seed weight, pulp with peel weight, leaf area, fruit length and fruit diameter were measured/recorded following the International Plant Genetic Resources Institute (IPGRI) descriptor by using digital balance (DJ-220 A, Japan), leaf area meter (Model-L1- 3100CSR. NO. LAM 1832 LICOR, USA) and slide calipers respectively. For biochemical evaluation, 5 different biochemical traits (TSS, TA, TSS/TA, Vitamin C and PH) were measured from the jujube fruit pulp.
Determination of titratable acidity (TA) Titratable acidity (TA) was determined according to the method [6], which was calculated using the formula:
Total Soluble Solids (TSS) The TSS of jujube pulp was determined by using a digital refractrometer (BOECO, Germany). Since difference in sample temperature could affect the measurement of TSS, each of the reading was standardized to a temperature of 20°C by adding 0.28% to obtain % TSS at 26 ± 1°C.
Ascorbic acid (Vitamin C) Ascorbic acid was determined according to the dye method, which was calculated using the following formula:
Determination of pH: The pH was determined by using a glass electrode pH meter (GLP 21, Crison, Barcelona, EEC). The pH meter was calibrated with buffers at pH 4.0 followed by pH 7.0, analysis of variance and comparison of means for qualitative and quantitative traits were performed using GeneStat 5.5. Descriptive statistics and cluster analysis & grouping of germplasm were done by single linkage method. In dendrogram, 5 clusters was taken among 42 jujube germplasm according to similarities and dissimilarities on the basis of morphological and biochemical traits.