Pythium huanghuaiense Jia J. Chen & X.B. Zheng 2021

Chen, Jia-Jia, Feng, Hui, Yu, Jian, Ye, Wenwu & Zheng, Xiaobo, 2021, Pythium huanghuaiense sp. nov. isolated from soybean: morphology, molecular phylogeny and pathogenicity, Biodiversity Data Journal 9, pp. 65227-65227 : 65227

Pythium huanghuaiense Jia J. Chen & X.B. Zheng 2021 sp. n.

Materials

Type status: Holotype. Occurrence: recordedBy: Jiajia Chen; Taxon : scientificName: Pythium huanghuaiense; class: Oomycetes ; order: Pythiales ; family: Pythiaceae ; genus: Pythium ; Location : country: China; stateProvince: Jiangsu; locality: Nanjing , Jiangning District , Pengfu Village ; Identification : identifiedBy: Jiajia Chen ; Event : year: 2016; month: 4; day: 29; habitat: on seedlings of Glycine max; Record Level : type: chen 94 (BJFC-C 1993, metabolically inactive culture); language: en Type status: Paratype. Occurrence: recordedBy: Jiajia Chen; Taxon: scientificName: Pythium huanghuaiense; class: Oomycetes; order: Pythiales; family: Pythiaceae; genus: Pythium; Location: country: China; stateProvince: Jiangsu; locality: Nanjing, Jiangning District, Pengfu Village ; Identification: identifiedBy: Jiajia Chen & Xiaobo Zheng; Event: year: 2016; month: 4; day: 1; habitat: on seedlings of Glycine max; Record Level: type: Chen 95 (NJAU-JN18, JAFLA 95; metabolically inactive culture) & Chen 96 (NJAU-JN19, JAFLA 96; metabolically inactive culture); language: en Type status: Paratype. Occurrence: recordedBy: Jiajia Chen; Taxon: scientificName: Pythium huanghuaiense; class: Oomycetes; order: Pythiales; family: Pythiaceae; genus: Pythium; Location: country: China; stateProvince: Anhui; locality: Suzhou ; Identification: identifiedBy: Jiajia Chen & Xiaobo Zheng; Event: year: 2016; month: 7; habitat: on seedlings of Glycine max; Record Level: type: Chen 99 (NJAU-JN30, JAFLA 99; metabolically inactive culture); language: en Type status: Paratype. Occurrence: recordedBy: Jiajia Chen; Taxon: scientificName: Pythium huanghuaiense; class: Oomycetes; order: Pythiales; family: Pythiaceae; genus: Pythium; Location: country: China; stateProvince: Shandong; locality: Jining ; Identification: identifiedBy: Jiajia Chen & Xiaobo Zheng; Event: year: 2016; month: 8; habitat: on seedlings of Glycine max; Record Level: type: Chen 100 (NJAU-JN65, JAFLA 100; metabolically inactive culture); language: en Type status: Other material. Occurrence: recordedBy: Jiajia Chen; Taxon: scientificName: Pythium huanghuaiense; class: Oomycetes; order: Pythiales; family: Pythiaceae; genus: Pythium; Location: country: China; stateProvince: Jiangsu; locality: Nanjing, Jiangning District, Pengfu Village ; Identification: identifiedBy: Jiajia Chen & Xiaobo Zheng; Event: year: 2016; month: 4; day: 29; habitat: on seedlings of Glycine max; Record Level: type: JAFLA 94, NJAU-JN11 (isotypes, metabolically inactive culture); language: en

Description

Pathogenic on soybean. Colonies submerged, with a cottony pattern on CMA, a rosette pattern on PCA and a cottony pattern on 10% V8A (Fig. 1 ). Average growth rates of 32.8 mm/day at 25°C on PCA (Fig. 2 ). Cardinal temperatures: minimum 4°C, optimum 25°C, maximum 37°C. Main hyphae hyaline, aseptate, up to 5.0 µm wide. Hyphal swellings globose, sub-globose, obturbinate to pyriform, mostly terminal or sometimes intercalary, 15-22.5 × 13.5-20 (mean 19 × 17.5) μm. Sporangia and zoospores not observed. Homothallic; oogonia globose, smooth or with a projection, terminal or intercalary, 12.5-18 μm (mean 15.5 µm) in diameter. Antheridia mostly monoclinous, sometimes hypogynous, one to two per oogonium; antheridial stalks unbranched, arising at various distances from oogonia; antheridial cells sub-globose, club-shaped or fist-shaped, making broad or narrow apical contact with oogonia. Oospores plerotic or nearly plerotic, globose, 11.5-17 μm (mean 14.5 µm) in diameter, hyaline. Oospore wall 0.5-1.5 µm (mean 1.1 µm) thick (Fig. 3 ).

Etymology

With reference to the distribution of the species in the Huang-Huai area of China.

Notes

Pythium huanghuaiense can be distinguished morphologically from its closest relatives, including P. mamillatum Meurs, P. paroecandrum Drechsler, P. spiculum B. Paul and P. wuhanense Y.Y. Long, J.G. Wei & L.D. Guo, by its narrower hyphae and relatively higher maximum growth rate. Additional differences between the novel species and other related species are listed in Table 2 .

Figures

Figure 1. Colony patterns of Pythium huanghuaiense (Chen 94) on A. CMA; B. PCA; and C. V 8 A.

Figure 2. Mycelial growth rate of isolates of Pythium huanghuaiense Chen 94, 95, 96, 99 and 100 on PCA at different temperatures.

Figure 3. Asexual and sexual reproductive bodies of Pythium huanghuaiense (Chen 94). A. Obturbinate hyphal swelling; B. globose hyphal swelling; C. sub-globose hyphal swelling; D. pyriform hyphal swelling; E, F. intercalary hyphal swellings; G, H. oogonia with a projections; I. nearly plerotic oospore; J. elongated antheridial cell wavy in contour; K. intercalary oogonium; L. Nearly plerotic oospore and two antheridia. Bars: A-E 10 μm; G-J 5 μm.