Breeding > What are endophytes?

What are endophytes?

Grass plants may contain an internally growing fungus called endophyte. Different strains of endophyte are available in many of the grass cultivars. The Standard strain implies that the cultivar contains a wild type endophyte which will help resist insect attack (eg Argentine stem weevil, Black Beetle), and help to prevent over-grazing but may, particularly in dry summer conditions, cause ryegrass staggers and reduce animal growth rates.

Low endophyte implies low or nil endophyte infection levels in the seed and its use is best suited to areas of low insect predation generally associated with high summer moisture. Novel strains are now being developed which may or may not cause ryegrass staggers but generally have some level of toxicity to some of the pasture insect species. Insect response to these strains is variable dependent on the strain of novel endophyte and the reaction of the grass cultivar to it.

Endophyte levels in seed generally decline in seed lines stored for more than a year under normal ambient conditions.

Endophyte viability can be improved by storing seed under conditions of low humidity and temperature. Seed lines can be tested for current and viable endophyte level.

Endophyte strain	Species	Potential Toxin Production (Toxins levels can vary between endophyte strain, host grass strain, growing conditions and seasonally.)					Comments
Endophyte strain	Species	Lolitrem B	Ergovaline	Janthitrem	Peramine	Loline	Comments
Standard “wild type” Also known as “feral”	N. lolii	moderate to high	moderate to high	nil	moderate to high	nil	Provides very good control of Argentine stem weevil and pasture mealy bug. Good control of black beetle larvae and adults. Low level of control of porina caterpillar. Can cause animal health problems during dry periods when excessive stem relative to leaf is grazed including ryegrass staggers and heat stress.
AR1	N. lolii	nil	nil	nil	high	nil	Provides very good control of Argentine stem weevil and pasture mealy bug. Variable control of root aphid. Mild deterrence to black beetle adults. Safe to the grazing animal. Recommended for dairy, sheep and cattle. Currently the only recommended safe endophyte for horses, deer and alpacas.
AR6/Endo5	N. lolii	nil	low to moderate	nil	moderate	nil	Provides good control of Argentine stem weevil and pasture mealy bug. Provides no control of black beetle larvae but some control of the adult. Do not use where conditions of prolonged set stocking occur. Avoid grazing fresh regrowth during summer and autumn.
NEA2	N. lolii	low to moderate	low to moderate	nil	moderate	nil	Similar in effect and control of insects to AR6.
AR37	N. lolii	nil	nil	high	high	nil	Provides good control of Argentine Stem weevil larvae but no control of adult weevils. No control of grass grub. Good control of pasture mealy bug. Good control of root aphid. Control of porina caterpillar. Provides no control of black beetle larvae but some control of the adult. No control of red headed or black headed pasture cockchafers. Not recommended for deer or horses. Can cause severe grass staggers for short periods.
AR542 Max P Also known as Max Q	N. coenophialum	nil	nil	nil	nil	low	Provides low to moderate control of Argentine stem weevil and black beetle. Reduces damage caused by black beetle adults and larvae. Good control of porina caterpillar. Small deterrence effect on grass grub feeding. Provides resistance to pasture mealy bug and has a small effect on root aphid. Safe to the grazing animal.

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Insect pest resistance of novel endophytes

Strain	Arg. Stem Weevil	Root Aphid	Mealy Bug	Black Beetle	Grass Grub	Cockchafer	Porina
AR1	High	Low	Low	Low	Nil	Nil	Nil
AR6	High	Medium	Medium	High	Nil	Nil	Nil
AR37	Larval	High	Medium	Medium	Nil	Nil	Larval
Endosafe	High	Medium	Medium	High	Nil	Nil	Nil
Max P	Medium	Medium	Medium	Medium	Nil	Nil	Low
U2/U12	Medium	High	High	Medium-High	High	High	High
NEA2	High	Medium	Medium	High	Nil	Nil	Nil
Wild type (Nui)	High	Low	Low	Medium-High	Nil	Nil	Low