Endophytes Flashcards
What areas in NZ will NOT show benefits from using endophytes?
Cooler regions such as Southland
What is the effect of endophytes on tiller density?
Greater in the endophyte infected pasture
Where is endophyte likely to improve pasture production?
Summer dry environments and insect challenged environments
How does ASW (argentine stem weevil) damage grass plants?
mining the central psuedostem and growing points
How much more dry matter did a standard-infected perennial ryegrass produce than one with no endophyte (%)
38%
What pests does Loline protect from?
ASW, grass grub, porina
What pests does Janthitrems protect from?
ASW, porina, root aphid, black beetle, pasture mealy bug
What pests do ergovaline protect form?
Black beetle
What pests does Lolitrem B protect from?
None but may interact with other alkaloids to protect from pests
What pests does peramine protect from?
ASW
What is the effect of black beetle on grass and where is it found?
feed on the roots underground, found in the central/upper North Island
What is the effect of grass grub and where is it found?
feed on the roots, found all over NZ
What is the mechanism which endophytes use to protect against insect pests?
produce alkaloids which minimize the amount of eggs being laid and the amount of feeding that larvae can do on the plant
What is the main alkaloid in Tall/Meadow Fescue
Lolines
What month is peramine in the highest concentration in ryegrass?
November
Explain the endophyte life cycle and transmission
Endophytes live in the seed. As the seed germinates, endophytes grow into the shoot and emerging tiller. The endophyte lives at the base of the plant/growing point. As new tillers get initiated the endophyte emerges and elongates with the tiller into the seed again as the plant becomes reproductive.
Define endophyte
Epichloe species. It is a fungus found inside perennial ryegrass and fescue plants which have a symbiotic relationship with the plant
How does a water deficit effect ergovaline and Lolitrem B concentrations in grass?
increases
How much higher did endophyte-infected ryegrass yield than non-infected in Summer and Autumn?
Summer - 20% + . Autumn 30%+
How much economic damage does the ASW cause to NZ pasture annually?
$46-200 million
What time of year does Ryegrass Staggers usually occur?
late summer/autumn
What is the effect of Lolitrem B on animals?
Blocks ion channels to prevent heart cells firing - tremogenic compound causing loss of control over muscles. Effects the motility of the gut, causing malabsorption of nutrients resulting in more dags. Ryegrass staggers.
Where can ergovaline be stored in Animals bodies?
Liver, kidneys, fat tissue
What effect does ergovaline have on animal health?
vasoconstrictor, reduces the size of veins and ability of the animal to regulate heat. Causes them to change their behaviour to regulate their body temperature eg searching for water which can cause them to drown. Death due to misadventure. Reduces prolactin and therefore reproduction and milk production
Where in the plant is Loline concentrated?
Leaves and roots
Where in the plant is Janthitrems concentrated?
Leaves, seed, seedhead
Where in the plant is ergovaline found ?
Leaf sheath, reproductive tillers, seed head, seed.
Where in the plant is Lolitrem B found?
Leaf sheath, reproductive tiller, seedhead, seed
Where in the plant is peramine found?
Young leaves
Name the endophyte strain found in Meadow Fescue (botanical name)
E. uncinata
Name the endophyte strain found in Tall Fescue (botanical name)
E.coenophiala
Name the endophyte strain found in perennial ryegrass (botanical name)
E. festucae var . lolli
Name 3 alkaloids in a wild type endophyte
peramine, lolitrem B, ergovaline
What effect does peramine have on animals?
None
What is the main way which endophytes decrease animal production?
Lower intake
What indirect effect does endophyte have on animal productivity?
reduced clover content due to increased grass production
How does endophyte impact per hectare performance?
may improve pasture production and persistence, more feed available to livestock and will increase production in the long-term which can offset effect of alkaloids on individuals
How do AR1, AR37, Wild type and no endophyte vary in their ability to protect against insect pests?
AR37 is the best and is comparable with the wild type endophyte. AR1 is not as good as AR37 or wild type endophyte but is better than NO endophyte at all.
What alkaloids are present in AR1
peramine
What alkaloids are present in AR37
Janthintrems - broad spectrum effect.
What alkaloids are present in wildtype?
peramine, lolitrem B, ergovaline
What alkaloids are present in NEA2
peramine and ergovaline
What alkaloids are present in NEA6
peramine and ergovaline
What alkaloids are present in AR5
peramine
What alkaloid is present in MaxP?
Loline
What alkaloid is present in Grubout?
Loline
What is the aim of developing novel endophytes?
aim is to get rid of alkaloids which produce harmful effects on animals whilst maintaining positive effects on pasture production and insect protection
how can the risk of ryegrass staggers be reduced through farm management?
Understanding where alkaloids are produced in the plant and how to avoid grazing these points
Compare the liveweight gains of lambs grazing wild type endophyte pastures vs non-infected pastures
41g/hd/d vs 111g/hd/d
Compare the rygrass staggers score of lambs grazing wild type endophyte infected pastures with no endophyte pastures
3.1 vs 0 out of 5
Compare the flystrike % of lambs on endophyte with a wild-type endophyte vs no endophyte
15% vs 2%
Compare the prolactin levels of cattle on wild type endophyte vs nil endophyte
90mg/ml vs 189mg/ml
What level of ergovaline causes clinical disease in CATTLE
300ppb
What level of ergovaline causes clinical disease in SHEEP
500ppb
What level of Lolitrem B results in clinical disease in both sheep and cattle?
1800ppb
What milk yield did cows in Autumn have on AR37, AR1 and Wild type endophyte ?
14.1, 14.9, 11.8
What milk yield did cows have grazing pastures on no endophyte in Autumn
14.2
