Stevia leaves contain various components, such as flavonoids, labdanes, chlorophylls, sterols, triterpenoids, mono-disaccharides, organic acids and inorganic salts. Stevia is known to accumulate diterpenoid steviol glycosides, which are approximately 300 times sweeter than regular sugar. Stevioside and rebaudioside A are the main diterpenic glycosides in stevia. Steviol glycosides are the secondary metabolites responsible for the sweetness of stevia. The main objectives of the present study were to determine the concentrations of diterpenic glycosides (stevioside and rebaudioside A) in three stevia varieties ( Stevia rebaudiana) via the HPLC-UV technique and to amplify the UGT76G1 gene by PCR using gene-specific primers. The expression levels of the UGT76G1 gene were determined in the three stevia varieties. The PCR products were sequenced and analyzed, and the nucleotide sequences of the UGT76G1 gene were submitted to GenBank and assigned to the following three varieties: Egy1 (MH087463), China1 (MH087464) and Sponti (MH087465). Cluster analysis was used to separate the three varieties into two major clusters based on their phylogenetic relationship. In addition, chemical analysis was carried out to evaluate stevioside and rebaudioside A. The present study concluded that Egy1 and Sponti are closely related varieties as they fall in the same cluster, while China1 forms a separate cluster. Bioprospecting studies could be useful for selection of superior ecotypes of Stevia rebaudiana .

Two field experiments were carried out in km 71 West Alexandria-Cairo desert Road during 2014/15 and 2015/16 seasons to study the response of some multigerm sugar beet varieties i.e., Top, Sultan and Kawemira to foliar spray with compost tea at three levels of (0, 15 and 20 L/fed/300 L water) at 45 and 75 days from sowing. The experimental design was a split plot design with three replicates, foliar spray with compost tea levels were arranged in the main plots and sugar beet varieties were allocated in the sub plots. The results showed that foliar spray with the level of 20 L/fed with compost tea significantly increased root length, diameter, fresh weight/plant, sucrose%, purity%, root and sugar yields/fed in both seasons, while, decreased root mineral contents (α amino N, Na and K %) as compared with zero treatment (control) or 15 L/fed level of compost tea. The Three tested varieties were differed significantly in the root length, diameter, fresh weight/plant, sucrose%, purity%, root and sugar yields/fed and root mineral contents. Kawemira variety surpassed the other two varieties (Sultan and Top) in the most traits in both seasons. Foliar spray with compost tea increased the numbers of two sugar beet insects, beet fly (Pegomya mixta Vill.) and tortoise beetle (Cassida vittata Vill.). Kawemira variety was less attracted by the two previous insects, during two successive seasons. Moreover foliar spray with compost tea at level 20 L/fed recorded the highest values for sucrose %, root and sugar yields/fed in both seasons. Generally, it could be recommended that sown Kawemira, Sultan and Top varieties, respectively and sprayed with 20 L/fed compost tea produced the highest sucrose%, root and sugar yields/fed and yield quality in a sandy soil.

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Four experiments were conducted at El-Sabahia (31°, 12N latitude), Alexandria, Egypt Sugar Cane Research Station to estimate the variability, heritability and flowering ability of eighty eight sugar cane germplasm. All experiments were planted in mid-March 2013 and their design was randomized complete block with three replicates. Variability in important traits among tested germplasm was estimated using genotypic and phenotypic variance in addition to genotypic and phenotypic coefficients and broad sense heritability. Flowering ability was determined using the number and percentage variation of flowering germplasm and flowering dates. The results showed that the magnitude of genotypic and environmental variance was the highest in number of millable cane character and the minimum value was found in stalk diameter in plant crop and both ratoon crops. Maximum genotypic and phenotypic coefficients of variation were exhibited by cane yield and number of millable cane in plant and both ratoon crops, also in single stalk weight and sugar yield in both ration crops. Among quality characters lowest values for both coefficients were obtained by purity percent in plant and both ratoon crops. In the present experiment, moderate to high heritability estimates were observed for all characters. The results indicated that the selection is more effective in plant and both ratoon crops based on yield contributing characters having high PCV, GCV and heritability along with suitable mean value. The flowering occurred in most of studied germplasm under natural environment in El-Sabahia area but the percentage of flowered germplasm differed among studied seasons. The flowering in sugarcane germplasm commenced from November and ended up to June. Most of the germplasm flowered during December at the three seasons and followed by February at plant crop, January and February at first ratoon crop and January and March at second ratoon crop. The tested germplasm were divided into 8 groups according to their flower ability.