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Öğe A CASE FOR ASSESSING ALLOCASUARINA AND CASUARINA SPP. FOR USE IN AGROECOSYSTEM IMPROVEMENT IN SEMI-ARID AREAS WITH A FOCUS ON CENTRAL ANATOLIA, TURKEY(Higher Education Press, 2021) Riley, Ian T.Agroecosystems in water-limited contexts-Mediterranean, semi-arid and arid climatic zones-are too frequently degraded systems that will not provide the needed ecosystem services to ensure a future of sustainable agricultural production. The processes that have created this situation continue and are being accelerated by anthropogenic climate change. Increasing arboreal vegetation in these areas through agroforestry is an important strategy to conserve and improve their agroecosystems. Actinorhizal trees and shrubs in the Casuarinaceae have a unique set of adaptations for heat and water stress, and/ or infertile to hostile soils. Central Anatolia, Turkey is particularly at risk of increasing aridity and further degradation. Therefore, species of Allocasuarina and Casuarina have been evaluated for their potential use in agroecosystem improvement in semi-arid areas with a focus on Central Anatolia. Based on a semiquantitative environmental tolerance index and reported plant stature, eight species were identified as being of high (A. verticillata and C. pauper) to moderate (A. acutivalvis, A. decaisneana, A. dielsiana, A. huegeliana, C. cristata and C. obesa) priority for assessment, with none of these species having been adequately evaluated for agroforestry deployment in semi-arid agroecosystems in any context. (C) The Author(s) 2019. Published by Higher Education Press.Öğe Colonization of Beauveria bassiana 08F04 in root-zone soil and its biocontrol of cereal cyst nematode (Heterodera filipjevi)(Public Library Science, 2020) Zhang, Jie; Fu, Bo; Lin, Qitong; Riley, Ian T.; Ding, Shengli; Chen, Linlin; Cui, JiangkuanCereal cyst nematodes cause serious yield losses of wheat in Hunaghuai winter wheat growing region in China. Beauveria bassiana 08F04 isolated from the surface of cysts is a promising biological control agent for cereal cyst nematodes. As the colonization capacity is a crucial criteria to assess biocontrol effectiveness for a microbial agent candidate, we aimed to label B. bassiana 08F04 for efficient monitoring of colonization in the soil. The binary pCAM-gfp plasmid containing sgfp and hph was integrated into B. bassiana 08F04 using the Agrobacterium tumefaciens-mediated transformation. The transformation caused a significant change in mycelial and conidial yields, and in extracellular chitinase activity in some transformants. The cultural filtrates of some transformants also decreased acetylcholinesterase activity and the survival of Heterodera filipjevi second-stage juveniles relative to the wild-type strain. One transformant (G10) had a growth rate and biocontrol efficacy similar to the wild-type strain, so it was used for a pilot study of B. bassiana colonization conducted over 13 weeks. Real-time PCR results and CFU counts revealed that the population of G10 increased quickly over the first 3 weeks, then decreased slowly over the following 4 weeks before stabilizing. In addition, the application of wild-type B. bassiana 08F04 and transformant G10 significantly reduced the number of H. filipjevi females in roots by 64.4% and 60.2%, respectively. The results of this study have practical applications for ecological, biological and functional studies of B. bassiana 08F04 and for bionematicide registration.Öğe Cryptically galled infructescence: a new sheoak gall type in Allocasuarina luehmannii and Casuarina pauper (Casuarinaceae)(Csiro Publishing, 2020) Riley, Ian T.Insect galls formed within the infructescences (cones) of Allocasuarina luehmannii and Casuarina pauper in southern New South Wales, Australia, are described. The galling was internal within the infested cones, which were small and irregularly developed, but could appear superficially normal except that they had a higher than normal proportion of samaras retained on bracteole dehiscence. Cross-sections revealed abnormal morphology and wasp larval chambers. All exit holes found were between bracteole pairs of either fertile or infertile florets. Emergent wasps were tentatively identified as Eurytoma sp. sensu lato (Hymenoptera: Eurytomidae). These cryptically galled infructescences represent a previously undescribed gall type in the Casuarinaceae and, for Eurytoma, potentially a rare instance of phytophagy in Australia. Infested cones were found in a season when normal cones in this drought affected area were not easily found. It was concluded that this phytophagy could negatively impact the regeneration potential of two already compromised sheoak species.Öğe Freezing impact on cone dehiscence, samara release, and seed germination in Casuarina cunninghamiana (Casuarinaceae)(Canadian Science Publishing, 2021) Riley, Ian T.; Saygi, A. HayriyeFreezing as a climatic extreme can contribute to patterns of plant distribution by potentially impacting mechanisms of seed release. Therefore, the impact of freezing on samara release and seed germination in infructescences (cones) of Casuarina cunninghamiana Miq. was assessed. Cones at field moisture content were frozen (22 h) and thawed (2 h) through zero to five cycles. Freezing impaired cone dehiscence and samara release (<1% samaras released with >= 2 freezing cycles) and reduced germination from frozen samaras still in the cone (30% to 50% loss in total germination with one to five freezing cycles, respectively). Seed germination from a sample of air-dried samaras was only mildly impacted (10% drop in total germination with five freezing cycles). This vulnerability of C. cunninghamiana to freezing damage, particularly samara release, appears to be a novel finding for woody perennials with fruiting structures that are retained in the canopy during winter. Vulnerability to freezing damage also appears to be a potential factor in species persistence and invasiveness.Öğe Identification of high-yielding wheat genotypes resistant to Pyrenophora tritici-repentis (tan spot)(Springer, 2021) Kokhmetova, Alma; Kumarbayeva, Madina; Atishova, Makpal; Nehe, Ajit; Riley, Ian T.; Morgounov, AlexeyTan spot, caused by Pyrenophora tritici-repentis, is a major foliar disease of wheat in Kazakhstan. This study evaluated 103 winter wheat genotypes for tan spot resistance and high-productivity traits in the field in two years. Entries were also characterized using the molecular marker Xfcp623, indicative of Tsn1 gene conferring sensitivity to Ptr ToxA. The proportion of entries insensitive to Ptr ToxA was relatively high (71%). Forty-eight entries with the lowest tan spot severity in the field were confirmed to be insensitivity to Ptr ToxA in the molecular screening. Entries which were resistant under field conditions had similar level of seedling resistance. Principal component analysis biplots showed, that all spike productivity traits were highly correlated. Days to heading (DH) and tan spot severity, as well as the normalized difference vegetation index and DH were strongly correlated. Thousand kernels weight (TKW) and plant height were highly correlated and both were negatively correlated with DH and tan spot severity, indicating that taller cultivars tended to be more resistant. The Xfcp623 negative entries had lower disease severity (by about 40%), flowered up to 2 days later than entries with Tsn1 and had significantly more spikelets per spike, number of grains per spike, TKW and grain weight/spike. The results of the study will be important for increasing the efficiency of breeding based on the elimination of the genotypes with dominant allele Tsn1. Of the 103 entries evaluated, 28 can be directly used in breeding programs to improve tan spot resistance and productivity of winter wheat.Öğe Infructescence and samara morphometrics and potential mechanism of samara release in Allocasuarina and Casuarina (Casuarinaceae)(Csiro Publishing, 2020) Riley, Ian T.In addition to samara aerodynamics, mechanisms of samara release will contribute to seed dispersal outcomes. Analysis of species descriptions of Australian members of the Casuarinaceae (sheoaks) indicated cone shrinkage to be a possible mechanism enhancing samara release. However, measurement of cones of nine species of Allocasuarina and Casuarina did not support this hypothesis, but outward movement of samaras both in the field and in oven-dried cones indicated that another mechanism was operating. Microscopic examination revealed that the proximal margins of the bracteoles are involute after drying, and it is postulated that incurving of the bracteoles during drying moves samaras outward against gravity enhancing samara release. This study also revealed inconsistencies in cone and samara metrics between field samples (1-3 specimens for 9 species) and the published descriptions. This could lead to identification uncertainties, and indicates the need to revise the descriptions to more fully encompass the variation in sheoaks across their natural and anthropogenic ranges.Öğe Phytophagous nematodes in cereal fields in Nigde Province, Turkey(Entomological Soc Turkey, Ege Univ, 2020) Toktay, Halil; Imren, Mustafa; Akyol, Badel G.; Evlice, Emre; Riley, Ian T.; Dababat, Abdelfattah A.This study evaluated the occurrence and incidence of phytophagous nematodes and identified the cereal cyst nematode species by morphological and molecular tools in the main cereal-growing areas in Nigde in 2018-2019. Phytophagous nematodes within twelve genera were detected in 95% of soil samples. The most common phytophagous nematodes in cereal soil were in the genera Heterodera, Ditylenchus, Merlinius, Pratylenchus, Aphelenchus, Aphelenchoides, Tylenchus, Helicotylenchus, Trophurus, Pratylenchoides, Filenchus and Xiphinema (in decreasing order of incidence). In particular, 75% of the soil samples from surveyed fields were infested with the cereal cyst nematodes (Heterodera spp.). Morphological characteristics of cysts and second-stage juveniles were calculated within the expected ranges for Heterodera filipjevi (Madzhidov, 1981) Stelter, 1984, however, two populations from Camardi was determined as Heterodera latipons Franklin, 1969 (Tylenchida: Heteroderidae). Intraspecific variation was not observed within the populations of H. filipjevi which could be in the same genotypic group. In addition to the high incidence of these Heterodera spp., intensive cereal cropping systems with/without non-cereal rotations in wheat production areas of Nigde also resulted in high incidence of root lesion nematode, Pratylenchus species.Öğe Samara water absorption and floatation in sheoaks, Casuarina and Allocasuarina (Casuarinaceae)(Page Press Publications, 2022) Riley, Ian T.; Qureshi, MoinDiaspores (samaras) of the sheoaks, Casuarina and Allocasuarina, have a mesocarp composed of hydrophilic fibres that, in Allocasuarina, rapidly expand on wetting, capturing significant quantities of water. The ecological function of this water capturing has been the subject of speculation but not quantification or experimentation. Therefore, the rate and quantity of water absorbed, and the floatation properties of samaras of accessions of Casuarina and Allocasuarina were assessed. Casuarina absorbed water slowly (~48 h) with median absorption of 90% (by weight) whereas Allocasuarina absorbed water rapidly (<2 min) with median absorption of 240%. The process was reversible and increasing in Allocasuarina, with median absorption reaching 400% over three to five wetting/drying cycles. The floating half-life of Casuarina and Allocasuarina samaras overlapped, 17-70 and 29-57 h, respectively, so Casuarina samaras were not shown to be better adapted to hydrochory. Based on five accessions of each genus, it does not be appear that water-capturing of sheoak samaras is directly related to habitat aridity, nor to potential hydrochory. Therefore, the ecological implications of differential water-capturing of sheoak samaras remains to be determined. © 2021 Ian T. Riley, Moin Qureshi
