This study aims to identifying and characterizing some molecular properties of geminiviruses co-infection in squash field crop cultivated in Egypt. Squash crops observed to be heavily infected with several insect vectors, also severe chlorosis and stunting was observed. Electron microscopic analysis has revealed geminate capsid particles which indicate the infection of Geminiviruses, especially SqLCV which represent an economic problem to squash filed crop in Egypt. We have investigated possible mixed infections with different plant viruses associated with chlorotic stunt diseases and or other genus groups of geminiviruses. The main objective of this study is to investigate the recombination events, possible recombinants and variants among these genera in the same family differing in vector transmission. This is the first report of the molecular characterization, phylogenetic analysis and putative recombination events of the full length genome of the Chickpea Chlorotic Dwarf Mastrevirus in Egypt. And the first report of co-infection with another begomovirus infecting squash plants. A full length clone of both viruses were isolated and characterized at the molecular level. The complete nucleotide sequence of DNA-A was determined (2,572 bp) and submitted to the genbank under accession no. KF692356. The isolate from Egypt has about 97.8 % homology with the Chickpea chlorotic dwarf virus (CpCDV) isolate from Syria DNA-A isolate FR687959, a 83.2 % homology with the Sudan isolate AM933134 and a 82.7 % homology with Pakistan isolate FR687960. To best of our knowledge this is the first report of complete genome of CpCDV that infect squash plants in Egypt and worldwide.

Bemisia tabaci (Gennadius) (Hemiptera, Aleyrodidae) is considered to be one of the most damaging pests in agriculture, causing severe losses in crops worldwide, affecting the tropical and subtropical regions. Random Amplified Polymorphic DNA-Polymerase Chain Reaction (RAPD-PCR) was used to assess the genetic diversity between different isolates collected from different regions in Egypt compared with some other worldwide isolates of this insect pest. Out of 12 primers 8 primers from Operon technology have shown to differentiate between 13 collected B. tabaci samples from all over Egypt and some other samples collected from different countries with two other populations representing biotypes A and B collected from the US used for biotype demarcation. Using 13 insect samples, RAPD analysis has produced a total number of 72 markers; about 68 polymorphic markers were revealed. The total number of bands obtained for each primer ranged from 4 to 14 within an average of 9 bands per primer. Of the pair wise combination among fifteen populations Ismailia population showed the highest similarity index (0.947), while US biotype A scored the lowest similarity index (0.326). Two major clusters were formed from the UPGMA dendrogram, which was constructed based on Dice similarity coefficient. RAPD-PCR screening demarcated the whitefly population based on the host species and genetic biotypes. Two major clusters have been revealed as A and B with two other minor clusters A1, A2, and B1, B2. Most of the samples collected from Egypt were clustered together in a minor cluster named A1. A1 group is divided into two sub-groups. A1a comprises the populations from Beni-Sweif in Upper Egypt, Ismailia, Kalyobia, El-Fayoum, Tanta, Kafr El-Sheikh, Alexandria, and A1b comprises Spain and Sudan. Group A1a is clustered together based on their host which belongs to the Cucurbitaceae family while Alexandria was separated individually based on its host which is cauliflower. Through the similarity matrix it could be concluded that the populations of Beni-Sweif, Ismailia, Kalyobia, El-Fayoum, Tanta, Kafr El-Sheikh had 80-90% similarity, while the Banha isolate had 30-40% similarity.ª 2015 Production and hosting by Elsevier B.V. on behalf

The production of new cultivars via recombinant DNA technology is important in applied agriculture. Promoters play fundamental roles in successful transformation and gene expression. Fragments of the upstream regulatory region of the movement protein gene of the Tomato yellow leaf curl virus (TYLCV; two fragments) and Watermelon chlorotic stunt virus (WmCSV, two fragments) and one fragment of the coat protein putative promoter of TYLCV (CPTY-pro) were isolated to assess their abilities to drive expression in monocot and dicot plants. We used bioinformatic analyses to identify tentative motifs in the fragments. The five promoter fragments were isolated, fused with the GUS reporter gene, and transformed into tomato, watermelon, and rice plantlets via Agrobacterium infiltration. GUS expression driven by each putative promoter was analysed using histochemical and fluorometric analyses. In both dicots and the monocots, the highest level of GUS expression was obtained using a truncated regulatory region from TYLCV (MMPTY-pro) followed by a truncated regulatory region from WmCSV (MMPWm-pro). However, the corresponding full-length fragments from TYLCV and WmCSV showed essentially equivalent expression levels in the fluorometric GUS assay compared with the enhanced Cauliflower mosaic virus e35S-pro. In addition, CPTY-pro showed no expression in either the dicots or the monocot. This study demonstrated that MMPTY-pro and MMPWm-pro may be useful as plant promoters.