สืบค้นงานวิจัย
Frequency of Occurrence and the Role of Colletotrichum Species on the Colletotrichum Leaf Fall Disease of Hevea brasiliensis in the Traditional Rubber Growing Regions of Kerala
Annakutty Joseph - ไม่ระบุหน่วยงาน
ชื่อเรื่อง (EN): Frequency of Occurrence and the Role of Colletotrichum Species on the Colletotrichum Leaf Fall Disease of Hevea brasiliensis in the Traditional Rubber Growing Regions of Kerala
ผู้แต่ง / หัวหน้าโครงการ (EN): Annakutty Joseph
บทคัดย่อ (EN): Colletotrichum leaf disease (CLD) is a serious problem causing considerable damage to the rubber plants in the nursery and immature plantations in the field. Tender leaves produced soon after bud burst during rainy season are affected and in severe cases the leaves become distorted, turn black, shrivel and fall off resulting in die-back of shoots. In high rainfall areas the shoot tips become devoid of leaves giving a pencil tip appearance through out the rainy season from June-November. Two species, C. acutatum and C. gloeosporioides are known to cause the disease. Hence an attempt was made to examine the occurrence and frequency of Colletotrichum spp. And the major cause of the Colletotrichum leaf fall disease of Hevea brasiliensis in the traditional rubber growing regions of Kerala. Diseased specimens were collected from different clones viz. RRIM 600, PB 260, RRII 105, RRII 414 and RRII 430 and about 140 locations of Kerala during 2010 and 2011 disease season. Leaf tissues showing different symptoms like typical raised spots, dark brown or black spots with yellow halo and dried margins were taken for isolation of the pathogen. Thirty to fourty leaf bits with disease symptoms were taken from every location and the pathogen was isolated on potato dextrose agar. The emerging colonies from each bit were initially characteirsed based on the conidial shape. The isolates were further characterised by colony colour, growth rate, perithecial production and sensitivity to carbendazim (2 ppm) by poisioned food technique. Pathogenicity of Glomerella sp was studied under in vivo condition by spraying the ascospores on the most susceptible clone RRII 105. Aggressiveness of two species was studied by estimation the toxin production. The toxic effect was tested by leaf puncture bioassay and leaf wilt bioassay using the crude culture filtrate of pathogens. On the basis of conidial morphology more than 65 % of the colonies were identified as C.acutatum in both the years. There were very few locations where either C.acutatum or C.gloeosporioides alone was recovered from the leaf bits. Both the species could be isolated from all types of symptoms. Isolates producing perithecia in culture were obtained from 31% of the sampling locations. Among the fast growing Colletotrichum isolates 24% produced the Glomerella cingulata teleomorph. None of the isolates identified as C. acutaum produced the perithecial or the ascigerous stage. Conidia of the C. acutatum was hyaline and elliptic to fusiform in shape, being tapered at one or both ends. Conidia of the all isolates of C. gloeosporioides and Glomerella sp. were oblong in shape, being obtuse or rounded at both end. Colony colour of the C. auctatum ranged from pale orange to cottony grey or grayish white with pink tinge on the upper surface and the reverse side of the colony was pink to salmon pink or creamy white in colour. Colony color of C.gloeosporioides was light grey to dark grey in the upper side and reverse was grey to dark grey, black or olive green to dark green. The isolates Glomerella sp and C.gloeosporioides grew faster and were more sensitive to carbendazim than isolates of C.acutatum. There was no significant differences in growth rate between the isolates Glomerella sp. And C.gloeosporioides. Both slow growth rate and less sensitivity to carbendazim differentiated C.acutatum from Glomerella sp. And C.gloeosporioides. However these characters may not be useful to distinguish between the isolates of Glomerlla sp. And C.gloeosporioides. Pathogenicity studies showed that perithecial isolates were equally pathogenic as the non-perithecial isolates of C.gloeosporioides. The lesions produced by C.acutatum was larger when compared to C.gloeosporioides and the perithecial strain. Studies on the impact of toxin production by two species revealed that C.acutatum as more aggressive with the large lesions and more wilting of the Havea leaves. The results of the present study confirm that C.acutatum is more predominant in the rubber growing regions of Kerala. The aggressiveness and the high frequency of occurrence indicate the C. acutatum is the main cause of the disease.
บทคัดย่อ: ไม่พบข้อมูลจากหน่วยงานต้นทาง
ภาษา (EN): en
เผยแพร่โดย (EN): การยางแห่งประเทศไทย
คำสำคัญ (EN): frequency of occurrence
เจ้าของลิขสิทธิ์ (EN): การยางแห่งประเทศไทย
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การอ้างอิง

Annakutty Joseph. "Frequency of Occurrence and the Role of Colletotrichum Species on the Colletotrichum Leaf Fall Disease of Hevea brasiliensis in the Traditional Rubber Growing Regions of Kerala". ไม่ระบุหน่วยงาน. ม.ป.ป.

Annakutty Joseph. "Frequency of Occurrence and the Role of Colletotrichum Species on the Colletotrichum Leaf Fall Disease of Hevea brasiliensis in the Traditional Rubber Growing Regions of Kerala". ไม่ระบุหน่วยงาน. ม.ป.ป.. Print.



TARR Wordcloud:
Frequency of Occurrence and the Role of Colletotrichum Species on the Colletotrichum Leaf Fall Disease of Hevea brasiliensis in the Traditional Rubber Growing Regions of Kerala
Annakutty Joseph
การยางแห่งประเทศไทย
ไม่ระบุวันที่เผยแพร่
Identification of Resistance of Hevea brasiliensis Clones to Corynespora Leaf Fall Disease Structural and Functional Characterization of a NBS-LRR Disease Resistance Gene Associated With Tolerance against Corynespora Cassiicola Causing Leaf Fall Disease in Rubber (Hevea brasiliensis) Control of Fusicoccum Secondary Leaf Fall on Hevea brasiliensis Surveillance on Corynespora Leaf Fall Disease: Incidence and Severity on Natural Rubber (Hevea brasiliensis) in Certain Hot Spots Areas in Kerala Performance of Selected Exotic and Indigenous Rubber (Hevea brasiliensis) Clones in Traditional Region of Kerala, India Components of Inorganic Phosphates in Rhizosphere of Rubber Tree (Hevea brasiliensis) Caffeic Acid O-Methyltransferase (COMT) Gene of the Pheny1 Propanoid Pathway Involved in Resistance to Corynespora Leaf Disease in Rubber (Hevea brasiliensis) FEASIBILITY OF RUBBER (Hevea brasiliensis Mull. Arg.) CULTIVATION IN THE EASTERN PROVINCE OF SRI LANKA; A NON TRADITIONAL AREA FOR RUBBER An Integrated Method for the Management of White Root Disease in Rubber Plantations in Sri Lanka Growth and Yield Performance of Some Exotic Clones Of Hevea brasiliensis in North Kerala Region
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