Male traits and herd reproductive capability in tropical beef cattle. 2. Genetic parameters of bull traits

A total of 4063 young bulls of two tropical genotypes (1639 Brahman and 2424 Tropical Composite) raised in northern Australia were evaluated for a comprehensive range of production and reproduction traits up to 24 months of age. Prior to weaning, peripheral blood concentrations of luteinising hormone (LH) and inhibin were measured at 4 months of age. At weaning (6 months) blood insulin-like growth factor-1 (IGF-I) and flight time were recorded. Body composition traits of fat depth and eye-muscle area were determined by ultrasonography at 15 months of age when additional measurements of liveweight, hip height and body condition score were recorded. Bull breeding soundness was evaluated at similar to 12, 18 and 24 months of age when measurements of scrotal circumference, sheath score, semen mass activity, progressive motility of individual sperm and percent morphologically normal sperm were recorded. Magnitude of heritability and genetic correlations changed across time for some traits. Heritability of LH, inhibin, IGF-I and of 18-month scrotal circumference, mass activity, progressive motility and percent normal sperm was 0.31, 0.74, 0.44, 0.75, 0.24, 0.15 and 0.25, respectively, for Brahmans and 0.48, 0.72, 0.36, 0.43, 0.13, 0.15 and 0.20, respectively, for Tropical Composites. Inhibin and IGF-I had moderate genetic association with percent normal sperm at 24 months in Brahmans but low to negligible associations in Tropical Composites. Body condition score in Brahmans and sperm motility (mass and individual) traits in both genotypes had moderate to strong genetic correlation with percent normal sperm and may prove useful candidates for indirect selection. There is scope to increase scrotal circumference by selection and this will be associated with favourable correlated responses of improved semen quality in both genotypes. The lack of genetic antagonism among bull traits indicates that selection for improved semen quality will not adversely affect other production traits.

First report of shoot blight of persimmon caused by Diaporthe neotheicola in Australia

Shoot blight symptom was found on persimmon (Diospyros kaki) in southern Western Australia in December 2010. The pathogen was isolated and identified as Diaporthe neotheicola on the basis of morphology, sequence analysis of the internal transcribed spacer (ITS) and the translation elongation factor 1-α (TEF). A pathogenicity test was conducted and Koch's postulates were fulfilled by re-isolation of the fungus from diseased tissues. This is the first report of D. neotheicola causing shoot blight on persimmon in Australia and worldwide. © 2012 Australasian Plant Pathology Society Inc.

A phylogenetic and taxonomic re-evaluation of the Bipolaris - Cochliobolus - Curvularia Complex

Three genera, Cochliobolus, Bipolaris and Curvularia form a complex that contains many plant pathogens, mostly on grasses (Poaceae) with a worldwide distribution. The taxonomy of this complex is confusing as frequent nomenclatural changes and refinements have occurred. There is no clear morphological boundary between the asexual genera Bipolaris and Curvularia, and some species show intermediate morphology. We investigated this complex based on a set of ex-type cultures and collections from northern Thailand. Combined gene analysis of rDNA ITS (internal transcribed spacer), GPDH (glyceraldehyde 3-phosphate dehydrogenase), LSU (large subunit) and EF1-α (translation elongation factor 1-α) shows that this generic complex divides into two groups. Bipolaris and Cochliobolus species clustered in Group 1 along with their type species, whereas Curvularia species (including species named as Bipolaris, Cochliobolus and Curvularia) clustered in Group 2, with its generic type. The nomenclatural conflict in this complex is resolved giving priority to the more commonly used established generic names Bipolaris and Curvularia. Modern descriptions of the genera Bipolaris and Curvularia are provided and species resolved in this study are transferred to one of these genera based on their phylogeny. © 2012 Mushroom Research Foundation.

Animal-Level Factors Affecting Ovarian Function in Bos indicus Heifers Treated to Synchronize Ovulation with Intravaginal Progesterone-Releasing Devices and Oestradiol Benzoate

The primary objective of this study was to investigate the impact of animal-level factors including energy balance and environmental/management stress, on the ovarian function of Bos indicus heifers treated to synchronize ovulation. Two-year-old Brahman (BN) (n = 30) and BN-cross (n = 34) heifers were randomly allocated to three intravaginal progesterone-releasing device (IPRD) treatment groups: (i) standard-dose IPRD [Cue-Mate (R) (CM) 1.56 g; n = 17]; (ii) half-dose IPRD [0.78 g progesterone (P4); CM 0.78 g; n = 15]; (iii) half-dose IPRD + 300 IU equine chorionic gonadotrophin at IPRD removal (CM 0.78 g + G; n = 14); (iv) and a control group, 2x PGF2a [500 mu g prostaglandin F2a (PGF2a)] on Day -16 and -2 (n = 18). Intravaginal progesterone-releasing device-treated heifers received 250 mu g PGF2a at IPRD insertion (Day -10) and IPRD removal (Day -2) and 1 mg oestradiol benzoate on Day -10 and -1. Heifers were managed in a small feedlot and fed a defined ration. Ovarian function was evaluated by ultrasonography and plasma P4 throughout the synchronized and return cycles. Energy balance was evaluated using plasma insulin-like growth factor 1 (IGF-I) and glucose concentrations. The impact of environmental stressors was evaluated using plasma cortisol concentration. Heifers that had normal ovarian function had significantly higher IGF-I concentrations at commencement of the experiment (p = 0.008) and significantly higher plasma glucose concentrations at Day -2 (p = 0.040) and Day 4 (p = 0.043), than heifers with abnormal ovarian function. There was no difference between the mean pre-ovulatory cortisol concentrations of heifers that ovulated or did not ovulate. However, heifers that ovulated had higher cortisol concentrations at Day 4 (p = 0.056) and 6 (p = 0.026) after ovulation than heifers that did not ovulate.

Phyllosticta spp. on cultivated Citrus in Australia

The occurrence of pathogenic and endophytic species of Phyllosticta on cultivated Citrus in Australia was investigated by DNA sequence analysis of specimens held in plant pathology herbaria and culture collections. Sequences of the internal transcribed spacer region (ITS1, 5.8S, ITS2), and partial translation elongation factor 1-alpha (TEF) gene of 41 Phyllosticta-like isolates from Citrus were compared to those sequences from the type specimens of Phyllosticta recorded from around the world. Phylogenetic analysis resolved all the sequences of Australian accessions into two major clades. One clade corresponded to P. citricarpa, which causes citrus black spot disease. The other clade contained P. capitalensis, which is a known endophyte of Citrus and many other plant species. All included herbarium accessions previously designated as Guignardia mangiferae are now designated P. capitalensis. No Australian isolates were identified as the newly described pathogens of citrus P. citriasiana or P. citrichinaensis, or the endophytes Guignarida mangiferae, P. brazilianiae, or P. citribraziliensis. © 2013 Australasian Plant Pathology Society Inc.

Molecular phylogenetic analysis reveals six new species of Diaporthe from Australia

Six new species of Diaporthe, D. beilharziae on Indigofera australis, D. fraxini-angustifoliae on Fraxinus angustifolia subsp. oxycarpa, D. litchicola on Litchi chinensis, D. nothofagi on Nothofagus cunninghamii, D. pascoei on Persea americana and D. salicicola on Salix purpurea from Australia are described and illustrated based on morphological characteristics and molecular analyses. Three of the new species no longer produced sporulating structures in culture and two of these were morphologically described from voucher specimens. Phylogenetic relationships of the new species with other Diaporthe species are revealed by DNA sequence analyses based on the internal transcribed spacer (ITS) region, and partial regions of the β-tubulin (BT) and translation elongation factor 1-alpha (TEF). © 2013 Mushroom Research Foundation.

Phyllosticta species on orchids (Orchidaceae), introducing Phyllosticta speewahensis sp. nov. (Phyllostictaceae, Ascomycota) from northern Australia

Several species of Phyllosticta (syn. Guignardia) have been described from orchids worldwide. A new species, Phyllosticta speewahensis, is proposed for a specimen isolated from leaf spots on a hybrid Vanda orchid in northern Queensland, Australia. Phylogenetic analysis of the nrDNA internal transcribed spacer region (ITS) and partial translation elongation factor 1-alpha (TEF1) gene sequences showed that P. speewahensis is most closely related to P. hostae. The likelihood that orchids harbour further cryptic species of endophytic and pathogenic Phyllosticta species is discussed.

Polyphasic characterization of four new plant pathogenic Phyllosticta species from China, Japan, and the United States

The black rot disease of Vitis species and other host genera of Vitacease is caused by Phyllosticta ampelicida and allied taxa which is considered to be a species complex. In this paper, we introduce four new species of Phyllosticta, including two from the P. ampelicida complex, based on a polyphasic characterization including disease symptoms and host association, morphology, and molecular phylogeny. The phylogenetic analysis was conducted based on the ribosomal internal transcribed spacer (ITS) region and a combined multi-locus alignment of the ITS, actin (ACT), partial translation elongation factor 1-alpha (TEF-1), and glyceraldehydes 3-phosphate dehydrogenase (GPDH) gene regions. Our study confirms the phylogenetic distinctions of the four new species, as well as their phenotypic differences with known species in the genus.

Green and brown bridges between weeds and crops reveal novel Diaporthe species in Australia

Diaporthe (syn. Phomopsis) species are well-known saprobes, endophytes or pathogens on a range of plants. Several species have wide host ranges and multiple species may sometimes colonise the same host species. This study describes eight novel Diaporthe species isolated from live and/or dead tissue from the broad acre crops lupin, maize, mungbean, soybean and sunflower, and associated weed species in Queensland and New South Wales, as well as the environmental weed bitou bush (Chrysanthemoides monilifera subsp. rotundata) in eastern Australia. The new taxa are differentiated on the basis of morphology and DNA sequence analyses based on the nuclear ribosomal internal transcribed spacer region, and part of the translation elongation factor-1α and ß-tubulin genes. The possible agricultural significance of live weeds and crop residues ('green bridges') as well as dead weeds and crop residues ('brown bridges') in aiding survival of the newly described Diaporthe species is discussed.

First report of Didymella americanaon baby lima bean (Phaseolus lunatus)

A new foliar disease was observed on baby lima bean (Phaseolus lunatus) in fields across western New York State, USA. The disease occurred in 10 fields with variable incidence and severity. Symptoms were initially necrotic, tan spots on leaves with red to reddish brown irregular margins that coalesced to encompass the entire leaf and cause abscission. Pycnidia were observed within the lesions. Isolations from diseased leaves yielded several pycnidial forming fungi, including a Didymella species. These isolates were characterized by morphology and sequencing of multiple reference genes (internal transcribed spacer (ITS), partial actin, β- tubulin (tub2), translation elongation factor 1-α (TEF), 28S rDNA large subunit (LSU), rpb2, and calmodulin). A four gene phylogeny (ITS, tub2, LSU, and rpb2) showed that the isolates from baby lima bean belonged to a well-supported clade that contained the type culture of Didymella americana. Pathogenicity of the isolates on three commonly grown cultivars of baby lima bean was confirmed. Symptoms that developed on inoculated plants were similar to those observed on diseased plants in the field. This is the first report of D. americana on baby lima bean.

Dry flower disease of Macadamia in Australia caused by Neopestalotiopsis macadamiae sp. nov. and Pestalotiopsis macadamiae sp. nov

Incidence of dry flower disease of macadamia (Macadamia integrifolia), expressed as blight of the flowers, necrosis and dieback of the rachis, is increasing in Australia. In the 2012/13 production season, incidence of dry flower disease resulted in 10% to 30% yield loss in the affected orchards. Etiology of the disease has not been established. This study was established to characterise the disease and identify the causal pathogen. A survey of the major macadamia producing regions in Australia revealed dry flower disease symptoms, regardless of cultivar or location at all stages of raceme development. Based on colony and conidial morphology, the majority (41%) of fungal isolates obtained from tissue samples were identified as Pestalotiopsis and Neopestalotiopsis spp. The phylogeny of the combined partial sequence of the internal transcribed spacer, beta-tubulin and translation elongation factor 1-alpha gene loci, segregated the isolates into two well supported clades, independent of location or part of the inflorescence affected. Further morphological examination supported the establishment of two new species, which are formally described as Neopestalotiopsis macadamiae sp. nov. and Pestalotiopsis macadamiae sp. nov. Using spore suspensions of isolates of both species, Koch?s postulates were fulfilled on three macadamia cultivars at all stages of raceme development. To our knowledge, this is the first report of species of Neopestalotiopsis and Pestalotiopsis as causal agents of inflorescence disease in macadamia.