No abstract

Wild blackberry species (Rubus spp. L.; Rosaceae) represents an invaluable source of genes for the generation of new varieties, but also serve as a primary source of disease inoculum. During April of 2020, symptoms of powdery mildew were observed on four populations of wild blackberry species located in the states of Chiapas (16°59'11"N, 92°59'07"W; 16°47'08"N, 92°31'05"W) and Michoacán (19°37'17"N, 100°08'59"W; 19°29'25"N, 101°32'54"W), Mexico. Signs of the pathogen were white powdery masses mainly on the top of new shoots. Symptoms included yellowing, necrosis, and early defoliation of the plants. Hyphae were tin-walled, hyaline, smooth, and 4.0–9.0 mm wide. Appressoria were indistinct -to- nipple-shaped. Conidiophores (n=30, 75–225 × 10.5–13.5 μm) were straight, and unbranched with cylindrical foot cells (n=30, 31.5–158 × 8–13.5 μm), straight, somewhat widening upwards, followed by 1–3 shorter cells. Conidia (n=100; 25.5–38.5 × 9.5–22.5 μm) were catenulate, ellipsoid-ovoid -to- doliiform, containing fibrosin bodies (in 3% KOH). Germ tubes (n=30, 13.5–40.5 × 4.5 μm) emerged laterally, and were unbranched with slightly swollen tips. Chasmothecia were not found. Morphological characters of the fungus in all samples corresponded to the previous descriptions of Podosphaera aphanis by Braun and Cook (2012) and Stevanovi´c et al. (2020). Voucher specimens were deposited in the Department of Agricultural Parasitology Herbarium at the Chapingo Autonomous University under accessions UACH421, UACH423, UACH425, UACH426. To confirm the species identification, the internal transcribed spacer (ITS) of one sample was amplified using the primers ITS5 (White et al. 1990) and P3 (Kusaba and Tsuge, 1995) and sequenced. The sequence was deposited in GenBank (accession number MW988591). A phylogenetic analysis using Bayesian inference and maximum likelihood was performed (Hernández-Restrepo et al. 2018) and included other Podosphaera species (Takamatsu et al. 2010). The sequence from the isolate UACH426 clustered with the strain MUMH1871 of P. aphanis forming a definite clade and remained as a sister taxon of P. pannosa. Pathogenicity was verified through inoculation by gently dusting conidia from one powdery mildew patch onto leaves of five healthy blackberry plants of each specie. The same number of noninoculated plants served as controls. All plants were maintained in a greenhouse at 25–30°C with 75% relative humidity. All inoculated plants developed powdery mildew symptoms after 12 days, whereas no symptoms were observed on noninoculated plants. The fungus recovered from the inoculated plants was morphologically identical to that originally observed on diseased blackberry plants, demonstrating the pathogenicity of the fungus. Based on morphological data and phylogenetic analysis, the fungus was identified as P. aphanis. This fungus has been reported to cause powdery mildew on blackberry plants in Serbia (Stevanovi´c et al. 2020). This is the first report of P. aphanis causing powdery mildew on wild backberry species in Mexico according to Farr and Rossman (2021). The primary source of inoculum of powdery mildew for commercial plantings is wild blackberry plants from noncultivated areas and may warrant control of wild populations.

Spearmint (Lamiaceae) is an aromatic herb widely cultivated in Mexico for its culinary, medicinal, and industrial properties. In May 2020, symptoms and signs of rust were observed in a two-ha commercial crop of spearmint in Cuautla, Morelos (18°50'26.6"N 98°57'31.9"W), Mexico. The disease incidence was 85% and the severity was 23%. Initial symptoms included chlorotic spots on the adaxial surface of the leaves. At advanced stages of the disease, necrotic spots surrounded by chlorotic halos were developed, and later the plants were defoliated. The signs were observed as numerous orange to reddish-brown erumpent pustules primarily on the abaxial surface of the leaves. Microscopic examination of the samples revealed the presence of subepidermal uredinia, erumpent, with hyaline and cylindrical paraphyses. Urediniospores (n = 50) were hyaline to light yellow, globose to obovoid, measuring 17-27  11-25 μm, including 0.6-0.7 μm wall thickness, individually supported on pedicels, echinulate, with two germinative pores. Morphological features of the fungus correspond with previous descriptions of Puccinia mentha by Kabaktepe et al. (2017). A voucher specimen (accession no. UACH448) was deposited in the Department of Agricultural Parasitology Herbarium at the Chapingo Autonomous University. To confirm identification, the 28S gene region of rDNA was amplified from one sample by a nested PCR using the primer sets Rust2inv (Aime, 2006) and LR6 (Vilgalys and Hester, 1990), and Rust28SF primers (Aime et al., 2018), and LR5 (Vilgalys and Hester, 1990) for the first and second reactions, respectively. The sequence of our specimen (GenBank accession No. OL878354) showed 100% homology (923/1304bp) with the type-specimen sequence of P. menthae (GenBank accession No. DQ354513) from Cunila origanoides from USA (Aime, 2006). Also, a phylogenetic analysis (Bayesian inference) including a published 28S dataset for Puccinia species was performed and the isolate UACH448 was grouped into a clade with P. menthae. Pathogenicity was demonstrated by spraying five ml of a suspension of urediniospores (1104 spores/ml) recovered from infected leaves onto leaves of ten healthy spearmint plants and ten noninoculated plants served as controls. All plants were maintained at temperatures from 28 to 35°C and relative humidity ranging from 70 to 80%. All inoculated plants developed the characteristic symptoms of the disease after 14 days, whereas the control plants remained symptomless. The pathogenicity test was performed twice with similar disease response. The morphological characteristics of the pathogen recovered from all the inoculated plants were identical to that originally inoculated, thus fulfilling Koch’s postulates. To our knowledge, this is the first report of Puccinia menthae causing leaf rust on Mentha spicata in Mexico. This species has been previously identified in Australia (Edwards et al. 1999), New Zealand (Beresford et al. 1982), and USA (Farr and Rossman, 2021) on Mentha spicata. This disease reduces considerably the quality of peppermint plants, so it is necessary to develop management strategies.

Penelitian ini bertujuan untuk menganalisis pengaruh antara tingkat pendapatan orang tua dan motivasi belajar terhadap hasil belajar siswa sekolah dasar di Kecamatan Sananwetan Kota Blitar. Penelitian ini termasuk jenis penelitian kuantitatif. Populasi dalam penelitian ini adalah siswa SD yang berada di wilayah Kecamatan Sananwetan Kota Blitar. Untuk menentukan sampel menggunakan teknik multistage sampling. Teknik pengumpulan data menggunakan angket dan tes hasil belajar. Teknik analisis data menggunakan Uji T dan Uji F dibantu dengan program SPSS. Kesimpulan penelitian ini: 1) terdapat pengaruh antara pendapatan orang tua terhadap hasil belajar, 2) terdapat pengaruh antara motivasi belajar terhadap hasil belajar dan 3) terdapat pengaruh antara pendapatan orang tua dan motivasi belajar terhadap hasil belajar siswa.