Molecular characterization and genetic diversity of cotton whitefly Bemisia tabaci infesting cotton crops
摘要
The Bemisia tabaci species complex is one of the most important vectors of emerging plant viral diseases, causing significant damage to a wide range of crops. This study aimed to assess the genetic variation and distribution of B. tabaci cryptic species in major cotton-growing areas of southern Punjab. A total of ninety whitefly samples were collected from cotton fields in seven districts including, Multan (15), Khanewal (15), Vehari (15), Lodhran (10), Bahawalpur (5), Muzaffargarh (15), and Dera Ghazi Khan (15). The collected samples were tested through polymerase chain reaction (PCR) using the specific primers (C1-J-2195/L2-N-3014 and MEAM-I F/R) for the identification of mitochondrial cytochrome oxidase I (mtCOI) gene for biotyping and it was found that 68% samples were positive with the tested primers. The positive samples were subjected to Single-Strand Conformation Polymorphism (SSCP) results revealed that the two samples collected from Mian Channu and Kabirwala locations showed distinct patterns. Mention accession nos. Sequencing of representative amplicons (accession numbers: MW564024, MW647909, MW578968 and MW579076) showed that the majority of the isolates clustered with the Asia II-1 clade, exhibiting 99–100% sequence identity to previously reported isolates from Pakistan, India, Afghanistan, and Indonesia. One isolate from Kabirwala showed closer affinity to Asia II-5, with approximately 93% identity to reference sequences. Based on these findings, Asia II-1 appears to be the predominant cryptic species in southern Punjab, whereas Asia II-5 was detected only at a single location (Kabirwala).