Name the soil which are removed for the capacity to hold motion
Answers
clay soil is your answer ok
Answer:
HESTOR OF PINE WILT NEMATODE:
Pine mortality in Japan was first reported Munemoto Yano in Nagasaki prefecture in 1905.
The nematode was first discovered in the timber of longleaf pine (Pinus palustris) in Louisiana, United States. Steiner and Burhrer reported that the nematode was a new species, and they named it Aphelenchoides xylophilus in 1934. In 1969, Japanese plant pathologists Tomoya Kiyohara and Yozan Tokushige discovered many unfamiliar nematodes on dead pine trees around the Kyushu islands in Japan. Then, they experimentally inoculated the nematode to healthy pine and other conifer trees and observed them. The healthy pine trees were killed—especially Japanese red and Japanese Black pine. However, Jack and Loblolly pine, Sugi cedar, and Hinoki cypress trees were able to survive. The researchers concluded that the nematode was the pathogen behind the increase of mortality in Japanese pine trees.
In 1972, the year after the ground-breaking paper of Kiyohara and Tokushige was published, Yasuharu Mamiya and T. Kiyohara posited that the nematode was the pathogen behind pine mortality, and that it was a new species. They named it Bursaphelenchus lignicolous . Bursaphelenchus lingnicolous, the Japanese nematode, was re-classified as the American species B. xylophilus in 1981.
Pine wilt nematode epidemics have occurred in Japan, particularly during warm, dry summers.
INTRODUCTION OF PINE WILT NEMATOD:
Bursaphelenchus xylophilus,
Commonly known as pine wood nematode or pine wilt nematode (PWN), is a species of nematode that infects pine trees and causes the disease pine wilt.It occurs in much of the United States, Canada, and Mexico. It also occurs in Japan, China, Taiwan, Korea, and Portugal.
Bursaphelenchus xylophilus
male with spicule visible
Scientific classification
Kingdom:
Animalia
Phylum:
Nematoda
Class:
Secernentea
Subclass:
Tylenchia
Order:
Aphelenchida
Superfamily:
Aphelenchoidoidea
Family:
Parasitaphelenchidae
Subfamily:
Bursaphelenchinae
Genus:
Bursaphelenchus
Species:
B. xylophilus
Binomial name
Bursaphelenchus xylophilus
(Steiner &
LIFE CYCLE: The pine wilt nematode has a typical nematode life cycle, with four juvenile stages and an adult stage with both male and female individuals that reproduce sexually. The mycophagous phase of the life cycle takes place in dead or dying wood, where the nematodes live and feed upon fungi, rather than the wood itself. The nematode cannot travel outside of the wood independently; it must be transported by an insect vector.
B. xylophilus has the shortest life cycle of any known parasitic nematode. In laboratory studies in which it is cultured on fungal media, its life cycle is completed in four days. In nature it reproduces most rapidly in the summer, producing large numbers of individuals that spread throughout the resin canal system of susceptible pines, into the trunk, the branches, and the roots. If living tree cells are no longer available the parasite feeds and reproduces on the fungal hyphae growing in the resin canals. In the fall and winter the parasite becomes inactive.
MECHANISM OF WILT AND SPREAD:
The mechanism from nematode infection to finally pine death is partially unknown now, but the outline has been recognized. The cause of pine death is stopping moving water in the timber. The phenomenon is caused by small bubbles, then air embolism of xylem tissue stops water movement. The embolism doesn’t make tylose or clog the nematode or pine cell. Why the several cavitation and non-reversible embolism occur, is unknown. In primary transmission, when the beetle feeds on a susceptible host pine, the pine wilt nematode enters the tree and feeds on the epithelial cells which line the resin ducts. This is referred to as the phytophagous phase of the nematode, and it results in pine wilt disease. Water transport in the tissues of the infested tree is disrupted, and the disease can manifest within a few weeks. Signs include browning of the needles or yellowing of the leaves, and the tree may die within two to three months.
GRADE OF RESISTANCE:
Furuno(1982) observed standing pine trees in Japanese forest, and ranked their resistance to pine wood nematode.The "High resistance" pines are rarely killed by the nematode, but young saplings or trees in weakened condition may succumb.
High resistance
Pinus taeda, P. elliottii, P. palustris, P. rigida, P. taiwanensis
Low resistance
P. strobus, P. massoniana, P. resinosa, P. tabulaeformis, P. banksiana, P. contorta