香蕉束顶病和花叶心腐病的快速测定技术研究

STUDY ON THE QUICK DIAGNOSIS FOR THE BUNCHY TOP DISEASE AND INFECTIOUS CHLOROSIS ( MOSAIC ) IN BANANA SUCKERS

种植无病蕉苗是防治香蕉束顶病和花叶心腐病的根本措施。筛选无病蕉苗的快速测定技术。除可引用2,3,5-氯化三苯基四(氨)唑浸渍徒手切片;在36℃条件下。24小时后:束顶病株叶脉切片的维管束呈现红色,其它组织为红褐色;花叶心腐病株叶脉切片(含维管束)全部呈现黑褐色;而健株叶脉切片由原绿色变成红色,最后褪成无色。此外。也可取叶片主脉的徒手切片,用1％曙红B水溶液染色。健株切片呈桔红色,病株切片呈砖红色,通过镜检:束顶病株叶片切片的表皮下,可观察到围绕在维管束周围成堆的分布有畸形叶绿体细胞团;花叶心腐病的畸形叶绿体细胞团,多分布在薄壁细胞中,且多散生;而健株的切片没有发现这种畸形的叶绿体细胞团,两种方法同样可靠。

Planting selectively disease-free suckers is the only measure for the prevention and control of bunchy top disease and infectious chlorosis in banana suckers. The rapid diagnostic technique for the disease-free suckers is as follow: Using 1% solution of 2, 3, 5-triphenyl tetrazolium chloride to immerse the sections of leave of the healthy or the diseased plants (from midribs) and keeping the temperature at 36℃, for 24 hr, then the bunchy top sections turn into brown-red colour, the vascular bundle turn into red, the sections of infectious chlorosis (Mosaic) turn into brown-black (including vascular bundle). While those from health suckers remain colourless at the last.In addition, using 1% solution Eosine B (dibromide nitrofluorescein sodium) to dye the sections of healthy or diseased plants (over sot, in 5-10 m.), 95% Ale. decoicur, the sections of healthy suckers turn into orange-red colour. The section of the diseased turns into brick-red colour. Under the microscope, it is observed that distortional chloroplast cells pile up around vascular bundle under the epidermis of midribs sections for bunchy top of banana, and the distortional chloroplast cells distribute in thin-wall cells for infectious chlorosis sections, but there are not any distortional chloroplast cells in the sections from healthy plant. Two methods are the same reliable.