ABSTRACT
Bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae (Xoo) is one of the most common devastating diseases of rice (Oryza sativa) all around the world. Thus, present study has been conducted to screen 12 aromatic rice cultivars (Atashail, Basmati, Kalizira, Uknimodhu, Zira katari, BR5, BR14, Bina dhan9, BRRI dhan34, BRRI dhan37, BRRI dhan38 and BRRI dhan50) for BLB resistant gene xa5. The genotypes were analyzed using two genetic markers (RM 122 and RM 390) by Polymerase Chain Reaction (PCR). Where, BR 14 that was resistant to BLB was used as control. Both primers generated different banding patterns. Primer RM 122 produced 6 bands whereas primer RM 390 produced 10 bands, respectively. The highest level of gene diversity value (0.8889) was observed in locus RM 390 and the lowest level of gene diversity value (0.7361) was observed in locus RM122 with a mean diversity of 0.8125. The PIC values ranged from a low of 0.7007 (RM 122) to a high of 0.8785 (RM 390) with an average of 0.7896. Using the linked primer RM 122, the bands of xa5 gene were standardized by the amplified DNAs. The DNA band of 246 bp was considered as resistance line and the DNA band of 230 bp was considered as a susceptible line. Similarly, in case of primer RM 390, 70 bp was considered as a resistance line and 112 bp was considered as susceptible line. Basmati, BRRI dhan50, Kalizira Atasail, Bina dhan9, Uknimodhu, BR 34, BR 37 and Zira Katari all of them found as partial resistant to BLB diseases. However, BRRI dhan38 was found as partial or complete susceptible cultivar.
ABSTRACT
Gumboro disease is caused by the infectious bursal disease virus (IBDV) which rapidly destroys immature B-lymphocytes of bursa of Fabricious, and causes immune suppression and high mortality in commercial broiler farms in Bangladesh. To investigate the possible effect of IBDV on lymphocytes and its distribution in the major lymphoid organs, bursa of Fabricious including spleen and thymus of naturally Gumboro-infected broilers, a research was conducted in the Department of Anatomy and Histology, collaboration with the Department of Pathology, Bangladesh Agricultural University, Bangladesh. Bursa of Fabricious, spleen and thymus of 21-days-old Gumboro-infected and non-infected broilers of same age (control) were routinely processed and stained by hematoxylin and eosin to examine the distribution of lymphocytes in the major lymphatic organs as well as quantified the number of lymphocytes under high power magnification field and compared with those of control. The number of lymphocytes in bursa of Fabricious, spleen and thymus of Gumboro-infected broilers were 27.20 ± 1.53, 66.50 ± 2.70 and 79.30 ± 3.92 whereas 121 ± 3.82, 89.90 ± 2.09 and 106.30 ± 4.07 were in non-infected control respectively. The numbers of lymphocytes were significantly (p < 0.05) lower in all lymphatic organs of Gumboro-infected broilers than those of non-infected control. The significant numbers of lymphocytes decrease in spleen and thymus suggest that IBVD not only destroy lymphocytes in bursa of Fabricious, but also in spleen and thymus and thus may severely suppress the immune response of IBVD affected broilers.
La enfermedad de Gumboro es causada por el virus de la bursitis infecciosa (VBI), que destruye rápidamente los linfocitos B inmaduros de la bolsa de Fabricio, y causa supresión inmune y la elevada mortalidad en las granjas comerciales de pollos de engorde en Bangladesh. Para investigar el posible efecto del VBI en los linfocitos y su distribución en los órganos linfoides principales, la bolsa de Fabricio, incluyendo el bazo y el timo de pollos de engorde naturalmente infectados con Gumboro, se realizó una investigación en el Departamento de Anatomía e Histología, y el Departamento de Patología, Universidad Agrícola de Bangladesh, Bangladesh. Tanto la bolsa de Fabricio, bazo y el timo de pollos de engorde con 21 días de edad infectados con Gumboro y no infectados de la misma edad (control) se procesaron de forma rutinaria y se tiñeron con H & E para examinar la distribución de los linfocitos en los órganos linfáticos principales, así cuantificar el número de linfocitos bajo campo de alta magnificación y compararlos con los de control. El número de linfocitos en la bolsa de Fabricio, bazo y timo de pollos infectados con Gumboro fue 27,20 ± 1,53, 66,50 ± 2,70 y 79,30 ± 3,92, respectivamente, mientras que en los controles no infectados fue 121 ± 3,82, 89,90 ± 2,09 y 106,30 ± 4,07 respectivamente. El número de linfocitos fue significativamente (p < 0,05) más bajo en todos los órganos linfáticos de pollos de engorde infectados con Gumboro que los no infectados. La disminuición significativa de linfocitos en el bazo y timo, sugiere que el VBI no sólo destruye linfocitos en la bolsa de Fabricio, sino también en el bazo y el timo y, por tanto, puede suprimir severamente la respuesta inmune de pollos de engorde afectados por VBI.