scholarly journals Black beetle damage to perennial ryegrass infected with AR1 endophyte

Author(s):  
A.J. Popay ◽  
J.G. Baltus

AR1 is a new fungal endophyte that is being released in perennial ryegrass to New Zealand farmers. This endophyte lacks the mammalian toxins, ergovaline and lolitrem B, but produces peramine which provides resistance to a major ryegrass pest, Argentine stem weevil (Listronotus bonariensis). Black beetle (Heteronychus arator) is another important pest of ryegrass in northern areas of New Zealand. Adults are selective feeders, and avoid feeding on ryegrass infected with wildtype endophyte. A limited supply of suitable food greatly reduces their reproductive capacity. Laboratory and field investigations were therefore carried out to evaluate the degree of resistance to black beetle provided by AR1. Assessments of adult black beetle feeding were made on two field trials planted in autumn 1999. In both trials, adult feeding was significantly higher on ryegrass infected with AR1 than on ryegrass with wild-type but also significantly lower on AR1 than on endophyte-free ryegrass. In a pot trial conducted in summer, black beetle adult damage to 4-week-old AR1-infected ryegrass was no different from damage to endophyte-free plants. However in 6-month-old plants, damage to AR1 plants was significantly less than to endophyte-free plants and was similar to damage levels on wild-type plants. A further pot trial showed that beetles overwintering on AR1 ryegrass had a higher reproductive capacity than those overwintering on wild-type infected ryegrass. In February 2001, two field trials planted the previous June were sampled for black beetle larvae. Black beetle presence was significantly higher on endophyte-free plots than on wild-type plots, with presence on AR1 intermediate between these treatments. Ryegrass infected with AR1, although showing a degree of resistance to black beetle compared with endophyte-free ryegrass, is more susceptible to damage than wild-type, particularly in its first year of planting. Limited data indicate that older AR1 swards may have similar resistance to that of the wild-type but further research is needed to clarify the effect of stand maturity on black beetle damage to ryegrass infected with this new endophyte. Keywords: AR1, black beetle, endophyte, Heteronychus, Listronotus, Neotyphodium, ryegrass

1999 ◽  
Vol 7 ◽  
pp. 113-122
Author(s):  
A.J. Popay ◽  
D.E. Hume ◽  
J.G. Baltus ◽  
G.C.M. Latch ◽  
B.A. Tapper ◽  
...  

A national series of six small plot trials were sown in 1996 and four in 1997 to evaluate the performance of six novel fungal endophytes in Grasslands Nui perennial ryegrass. These endophytes do not produce the mammalian toxins, ergovaline and lolitrem B, but produce peramine, a feeding deterrent to the major ryegrass pest, Argentine stem weevil (ASW). Trials included the naturally occurring endophyte (wild-type) which produces both toxins, and an endophyte-free (nil) treatment. Pasture production was measured regularly and samples were taken at least once each summer-autumn from all trials for assessment of ASW damage. Black beetle larval damage was recorded on three trials. The toxin-free endophytes, AR1, AR12, AR22 and the wild-type were equally effective at reducing ASW adult feeding and larval damage significantly below that which occurred in nil treatments. Ryegrass infected with AR1, AR12, AR22 and the wild-type endophyte was damaged less by black beetle larvae than ryegrass without endophyte. The effect of AR24 on insect damage was variable and two other toxin-free endophytes, AR17 and AR506, which had low infection rates, seldom reduced either ASW or black beetle damage. Yield differences between treatments were found on two of 21 sampling occasions between October and December and 12 of 30 sampling occasions between January and April. During summer-autumn, wild-type, AR1, AR12 and AR22 gave higher ryegrass yields than the nil, AR17 and AR506 treatments. In the second year of the 1996-sown trials, productivity of ryegrass with AR1 in the summer-autumn tended to be lower than that of the wild-type with significant differences occasionally occurring. Yield differences were correlated with either ASW or black beetle damage in North Island trials and with percent endophyte infection at all sites. Differences in yield at Lincoln, Canterbury, were attributed to pasture mealy bug. Three conclusions were drawn from these results: 1. Endophytes are very important for maximising ryegrass yield during summer and early autumn. 2. The effect of endophytes on yield is at least partly due to the insect resistance they impart. 3. The field performance of three toxin-free endophytes, AR1, AR12 and AR22, equalled that of the wild-type in terms of increased insect resistance but did not always match it in plant growth. Keywords: AR1, Argentine stem weevil, black beetle, endophyte strain, ergovaline, insect damage, lolitrem B, Neotyphodium lolii, ryegrass yield


Author(s):  
L.R. Fletcher ◽  
A.J. Popay ◽  
B.A. Tapper

The fungal endophyte Acremonium lolii, in association with its ryegrass host, produces both peramine, a feeding deterrent to Argentine stem weevil,andlolitrem B,a neurotoxin causing ryegrass staggers. Endophyte strains vary in the ratio of production of these alkaloids in the ryegrass. In field evaluations of several endophyte/ryegrass - combinations, 'Endosafe', a zero lolitrem B, high peramine strain protected its host against Argentine stem weevil attack and did not cause ryegrass staggers in lambs grazing three of four ryegrass cultivars. Lambs on the endophyte-free and Endosafe combinations had the highest liveweight gains and while endophyte-free ryegrass did not cause ryegrass staggers it suffered significant stem weevil damage. Ryegrasses with their 'wild-type' endophyte and a high lolitrem B strain 'Waiau', had only minor stem weevil damage but caused severe ryegrass staggers and weight loss in lambs. Ryegrass with the no lolitrem B, low peramine strain, 'IOOA', suffered some stem weevil damage and although not causing ryegrass staggers, did cause weight loss in lambs. Ryegrass/endophyte metabolites in addition to lolitrem B may have affected animal performance on endophyte-infected ryegrass. Keywords endophytc, Endosafe, perennial ryegrass,ryegrass staggers, Argentine stem weevil, liveweight gains, peramine, lolitrem B


Author(s):  
Louise M. Hennessy ◽  
Alison J. Popay ◽  
Travis R. Glare ◽  
Sarah C. Finch ◽  
Vanessa M. Cave ◽  
...  

AbstractArgentine stem weevil adults (ASW, Listronotus bonariensis) feed on the leaves of agricultural grasses and their larvae mine the pseudostem, causing extensive damage that can result in plant death. Plants emit volatiles that serve as signals to host-searching insects and these odours can be altered by both herbivory and fungal endophyte-infection. This study investigated whether ASW adults utilise olfaction to identify their host plants, perennial ryegrass (Lolium perenne), and if conspecific herbivory or the presence of Epichloë festucae var. lolii fungal endophytes (strain wild-type or AR1) influenced such responses. Results from olfactometer bioassays established that ASW adults were able to utilise their olfactory response to orient towards volatiles released by perennial ryegrass and further, the weevils displayed a preference for plants previously damaged by conspecific weevils. However, there was no evidence that weevils had the ability to distinguish between endophyte-infected and endophyte-free plants using olfaction alone. Using a push–pull extraction technique, thirteen volatile compounds were identified in the blend released by perennial ryegrass. Endophyte and herbivory were found to alter these volatile compounds and quantities emitted by this forage grass. This study suggests that despite observing differences in the plant volatile blend, ASW do not perceive endophyte (wild-type and AR1) using olfaction alone and must rely on other cues, e.g. contact chemoreception or post-ingestional malaise, to detect the presence of a bioactive endophyte in an otherwise acceptable host plant.


1989 ◽  
Vol 112 (2) ◽  
pp. 179-184 ◽  
Author(s):  
P. M. Sanders ◽  
D. J. Barker ◽  
G. S. Wewala

SummaryThe analysis of Kennedy et al. (1985) was applied to 150 individuals from each of six plots containing mixtures of the perennial ryegrass (Lolium perenne L.) cultivar Grasslands Nui and the resident ryegrass population at Rawhiti, Central Wairarapa, New Zealand. Four alleles (A, B, C and D) were identified at the phosphoglucoisomerase-2 allozyme locus in the two ryegrass populations. Using the maximum likelihood method, non-linear models were fitted to calculate the percentage contribution of Grasslands Nui to the mixtures. The contribution of Grasslands Nui to the six evaluation plots ranged from 5 to 44%, with S.E.S of 11–17%. The lowest contribution occurred under set stocking with sheep and a low fertilizer regime. The persistence of Grasslands Nui under contrasting grazing managements and fertilizer regimes in this dry environment, and aspects of enzyme electrophoresis application to field trials, are discussed.


2012 ◽  
Vol 63 (10) ◽  
pp. 927 ◽  
Author(s):  
Errol R. Thom ◽  
Alison J. Popay ◽  
David E. Hume ◽  
Lester R. Fletcher

The main plant species relied on for forage supply to grazing animals in New Zealand and south-eastern Australia is perennial ryegrass (Lolium perenne L.). Perennial ryegrass has evolved with a fungal endophyte (Neotyphodium lolii, Latch, Christensen & Samuals) that occupies intercellular spaces, and is nourished by its host. The endophyte (referred to as standard or wild-type) provides the plant with protection from a range of insect pests by producing alkaloids, some of which are also toxic to grazing animals, causing ryegrass staggers and/or exacerbating heat stress. Over the last 20 years naturally occurring perennial ryegrass endophytes have been found in Europe that produce less of the alkaloids that cause animal health problems but have similar or enhanced effects as the standard endophyte on deterring insect attack on infected plants, when introduced into New Zealand and Australian-bred ryegrasses. This review provides a summary of endophyte research in New Zealand from the perspective of insect pests, plants (particularly perennial ryegrass) and the animals grazed on ryegrass-dominant pastures. The protocols used to evaluate perennial ryegrass/endophyte associations over the past 30 years are also discussed. Future testing of new grass/endophyte associations should include the utilisation of more environments for agronomic and entomological experiments; routinely carrying out small animal toxicology assays, and the running of short-term indoor feeding experiments with sheep and cows. Implementation of these changes provides the minimum requirements for strengthening the evaluation of new endophyte associations so farmers using these technologies, gain optimal benefits from their adoption.


Author(s):  
V.T. Burggraaf ◽  
E.R. Thom

Perennial ryegrass pastures in New Zealand are usually established from seed naturally infected with the wildtype endophyte. New pastures can now be sown with perennial ryegrass that has no endophyte or has been infected with a new endophyte. Cows can contaminate pastures by consuming ryegrass seed infected with the wild-type endophyte on old pastures, and transferring the seed in their dung onto new pastures. A quarantine period before grazing new pastures may allow cows to eliminate wild-type endophyte-infected perennial ryegrass seed from their digestive tract, preventing contamination from this source. A trial was run at Dexcel, Hamilton, to define an appropriate quarantine period. Cows grazed wild-type (high endophyte) ryegrass pastures containing seedheads for 4 days before grazing Lotus corniculatus (quarantine pasture) for a further 4 days. This procedure was repeated five times from November 2000 to April 2001. Dung samples were collected daily after shifting cows off high endophyte ryegrass. Pastures contained viable ryegrass seed on seedheads from December to April, and ryegrass seedlings germinated in dung samples collected from January to April. Viable endophyte-infected perennial ryegrass seed was present in dung for 2 days after removal from the seed source, with 0.8% of the seed eaten remaining viable. Ryegrass seed endophyte viability was reduced from 100% to 40% after passage through the digestive tract of the cows. It is recommended that cows do not graze endophyte-free pastures or those sown with ryegrass containing a new endophyte for at least 2 days after grazing high endophyte ryegrass pastures containing ryegrass seedheads. Keywords: dairy cows, dung, perennial ryegrass, ryegrass endophyte, seedheads, seed transfer


2014 ◽  
Vol 44 (1) ◽  
pp. 28-35 ◽  
Author(s):  
Amy L. Klocko ◽  
Richard Meilan ◽  
Rosalind R. James ◽  
Venkatesh Viswanath ◽  
Cathleen Ma ◽  
...  

The stability and value of transgenic pest resistance for promoting tree growth are poorly understood. These data are essential for determining if such trees could be beneficial to commercial growers in the face of substantial regulatory and marketing costs. We investigated growth and insect resistance in hybrid poplar expressing the cry3Aa transgene in two field trials. An initial screening of 502 trees comprising 51 transgenic gene insertion events in four clonal backgrounds (Populus trichocarpa × Populus deltoides, clones 24-305, 50-197, and 198-434; and P. deltoides × Populus nigra, clone OP-367) resulted in transgenic trees with greatly reduced insect damage. A large-scale study of 402 trees from nine insertion events in clone OP-367, conducted over two growing seasons, demonstrated reduced tree damage and significantly increased volume growth (mean 14%). Quantification of Cry3Aa protein indicated high levels of expression, which continued after 14 years of annual or biannual coppice in a clone bank. With integrated management, the cry3Aa gene appears to be a highly effective tool for protecting against leaf beetle damage and improving yields from poplar plantations.


2021 ◽  
Vol 17 ◽  
Author(s):  
Pierre Beukes ◽  
Andrea Babylon ◽  
Wendy Griffiths ◽  
Simon Woodward ◽  
Electra Kalaugher ◽  
...  

The objective of this study was to predict the future performance of perennial ryegrass in the Upper North Island, New Zealand. The Basic Grassland model, BASGRA, was used with historic, current and future daily climate data as input, and soil water holding capacity, to predict changes in perennial ryegrass performance in space and time. The study focussed on land of ≤7° slope north of the town of Tokoroa and considered two potential warming pathways to the end of the 21st century. Persistence was defined as the time in years for the ryegrass sward to decline to 50% ground cover. The results for the two climate pathways were largely consistent with each other. Persistence should remain in the medium category (2.5-3.4 years, 10-12 t DM/ha) for the rest of this century for Bay of Islands, Whangarei, South Waikato/Tokoroa, and Rotorua. Persistence is predicted to change from medium to predominantly low (0-2.4 years, <10 t DM/ha) for Far North, Dargaville, DairyFlat/Rodney, Waiuku/Pukekohe and northern and central parts of Waikato. Coastal regions of Bay of Plenty were predicted to be poorly suited to perennial ryegrass and to remain so into the rest of the century. Large parts of the Upper North Island that are currently borderline for perennial ryegrass are predicted to become unsuitable for the species.


Agrikultura ◽  
2015 ◽  
Vol 26 (1) ◽  
Author(s):  
Kartika Sari

ABSTRACTNutrient Enhancement In Cereal Crops Using Actinobacterial EndophytesWheat high demand without sufficient production and Actinobacterial endophytes usage limitation inIndonesia motivated this research. The aim was to determine Actinobacterial endophytes effect on nutrientenhancement in wheat (Triticum aestivum L.). It was hypothesized that they can enhance wheat nutrient.The experiment stages were: 1) Pot-Trial I, confirming nutrient enhancement using Actinobacteria in 6 soiltypes; 2) Pot-Trial II, screening Actinobacteria strains; and 3) Field-Trial. The results showed thatActinobacteria effects varied for different nutrients and site based differences. In Pot-Trial I, different soiltypes significantly affected the manganese and zinc content (P=0.00 and P=0.01), but not inoculation ofActinobacteria nor the combination of them. Field Trials showed the same trends. Combination betweenthose treatments significantly affected manganese content (P=0.045). Nutrient analysis on xylem sap in PotTrials 2 only showed the value differences since there was insufficient collected volume to be statisticallyanalyzed. Zinc and iron contents were the highest in Actinobacteria EUM165 treatment and the highestmanganese content in Actinobacteria EN16. In conclusion, wheat nutrient content is affected byActinobacteria and different soil types but there was insufficient evidence to generally conclude that it canbe enhanced. They have their own effects and affected each other in enhancing nutrient content.Keywords: Nutreint, wheat, endophytic ActinobacteriaABSTRAKTingginya permintaan gandum tidak disertai produksi yang cukup, serta terbatasnya pemanfaatanActinobacteria endofit di Indonesia, melatarbelakangi penelitian ini. Tujuannya untuk mengetahuipengaruh penambahan Actinobacteria endofit terhadap nutrisi gandum (Triticum aestivum L.). Diduga,penambahan Actinobacteria endofit dapat meningkatkan kandungan nutrisinya. Tahapan penelitianmeliputi: 1) Uji-Pot I, mengonfirmasi peningkatan nutrisi gandum menggunakan Actinobacteria pada 6 jenistanah; 2) Uji-Pot II, menguji berbagai strain Actinobacteria terhadap peningkatan nutrisi gandum; serta 3)Uji Lapangan. Hasilnya menunjukkan bahwa Actinobacteria meningkatkan nutrisi gandum secara berbedatergantung nutrisi yang diuji serta jenis tanah yang digunakan. Pada Uji-Pot I, jenis tanah berpengaruhnyata terhadap kandungan mangan dan seng (P=0.00 dan P=0.01), tapi pemberian Actinobacteria maupunkombinasi keduanya tidak. Uji Lapangan menunjukkan hasil yang sama. Kombinasi kedua perlakuanmeningkatkan kandungan mangan secara signifikan (P=0.045). Analisis cairan xilem dari Uji-Pot IImenunjukkan perbedaan hasil tanpa uji statistik karena terbatasnya cairan yang dikumpulkan. Kandungantertinggi seng dan zat besi ditunjukkan oleh perlakuan Actinobacteria EUM165 dan mangan yang lebihtinggi oleh Actinobacteria EN16. Disimpulkan bahwa kandungan nutrisi tanaman gandum dapatdipengaruhi oleh pemberian Actinobacteria endofit serta perbedaan jenis tanah, namun tidak cukup buktiuntuk menyimpulkannya secara umum. Baik jenis tanah maupun Actinobacteria endofit memiliki pengaruhsendiri serta saling mempengaruhi terhadap kandungan nutrisi tanaman gandum.Kata kunci: Nutrisi, gandum, actinobacteria endofit


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