15/07/2014

Ba loài Địa y mới ở Hoà Bình, Tuyên Quang

dia-y-Willeya-pallidopora-laevigata-fusca-protrudens
Các ảnh A-C- thuộc loài Willeya pallidopora, D-F- thuộc loài Địa y lồi Willeya protrudens, G-H- thuộc loài Địa y sậm Willeya fusca; I- thuộc loài Địa y nhẵn Willeya laevigata. Ảnh Gueidan et al. British Lichen Society, 2014. 
(BiodiVn) - Địa y bao gồm các loài thực vật nhỏ, rất phổ biến nhưng lại ít được nghiên cứu ở Việt Nam. Chúng thường mọc bám trên các vỏ cây, phiến đá ẩm với màu đặc trưng như nấm mốc xám trắng. Có lẽ vì thiếu tư liệu mà đa đạng các loài địa y ở Việt Nam ẩn chứa nhiều tiềm năng cần được các nhà khoa học khám phá. Cũng vì thế, khả năng phát hiện loài mới ở nhóm thực vật này là rất lớn.
Theo BiodiVn cập nhật thì hồi tháng 6 vừa qua, một nhóm các nhà khoa học đã Phát hiện loài địa y mới Graphis upretii và ghi nhận bổ sung bẩy loài địa y cho Việt NamVừa xong, chúng tôi lại nhận được một bài báo công bố 3 loài Địa y mới thuộc chi Willeya phát hiện từ Việt Nam. Công bố này được ba nhà khoa học là Đỗ Văn Trường, Lữ Thị Ngân (Bảo tàng Thiên nhiên Việt Nam - Hà Nội - Việt Nam) và Cécile Gueidan (Bảo tàng Lịch sử Tự nhiên - Luân Đôn - Anh) mô tả và phát hành trên tạp chí The Lichenologist (Tập 46, số 4, trang 515–533, tháng 7, 2014) của Hội Địa y Anh. 

Các loài mới gồm những loài dưới đây.

1. Địa y sậm Willeya fusca Gueidan sp. nov.
Phân bố: Khu BTTN Hang Kia - Pà Cò, Mai Châu, Hoà Bình

2. Địa y nhẵn Willeya laevigata Gueidan sp. nov.
Phân bố: Pà Cò, Mai Châu, Hoà Bình.

3. Địa y lồi Willeya protrudens Gueidan sp. nov.
Phân bố: Khu BTTN Na Hang, Tuyên Quang; Khu BTTN Hang Kia - Pà Cò, Mai Châu, Hoà Bình; Lạc Nông, Bắc Mê, Hà Giang. 

Ngoài ra nhóm tác giả còn đề nghị đưa ra 7 các tên mới (tên hợp nhất) như sau: 
1. Willeya australis (Groenh.) Gueidan comb. nov. (Staurothele australis Groenh.)
2a. Willeya diffractella (Nyl.) Mull. Arg. var. diffractella (Verrucaria diffractella Nyl.)

2b. Willeya diffractella (Mull. Arg.) Gueidan var. flavicans comb. nov. (Staurothele diffractella var. flavicans Mull. Arg.)

3. Willeya iwatsukii (Harada) Gueidan comb. nov. (Staurothele iwatsukii Harada)

4. Willeya japonica (B. de Lesd.) Gueidan comb. nov. (Staurothele japonica B. de Lesd.)

5a. Willeya malayensis (Zahlbr.) Gueidan comb. nov. var. malayensis (Staurothele malayensis Zahlbr. var. malayensis)

5b. Willeya malayensis var. vegetior (Zahlbr.) Gueidan comb. nov. (Staurothele malayensis var. vegetior Zahlbr.)

6. Willeya microlepis (Zahlbr.) Gueidan comb. nov. (Staurothele microlepis Zahlbr.)

7. Willeya pallidopora (P. M. McCarthy) Gueidan comb. nov. (Staurothele pallidopora P. M. McCarthy)



Phylogeny and taxonomy of Staurothele (Verrucariaceae, lichenized ascomycetes) from the karst of northern Vietnam
Cécile GUEIDAN, Truong VAN DO and Ngan Thi LU
Abstract: The crustose genus Staurothele (Verrucariaceae, Ascomycota) is a common component of the lichen flora from subneutral to alkaline silicate rocks in temperate to cold-temperate climates. Our field study in the karst system of northern Vietnam showed that it is also common on dry to humid limestone in the wet tropics. Molecular data revealed that species of Staurothele from Vietnam belong to an unnamed clade sister to the genus Endocarpon, together with the tropical Australian species Staurothele pallidopora and Staurothele diffractella, a North American species recently transferred to Endocarpon based on molecular data. The genus Willeyais here resurrected for this clade of crustose epilithic Staurothele with pale ascospores. Eight new combinations are proposed and three new species of Willeyaare described from Vietnam. Sampling tropical members of a lichen family previously mostly known from temperate areas contributed significantly to improving its generic classification.

Key words: classification, Endocarpon, generic delimitation, lichens, Verrucariales, Willeya

dia-y-Willeya-pallidopora-laevigata-fusca-protrudens-2

Photos Gueidan et al. British Lichen Society, 2014.

Willeya fusca Gueidan sp. nov.

MycoBank No.: MB807220. Differing from other species of Willeyaby its dark brown areolate thallus.

Type: Vietnam, Hoa Binh Province, Mai Chau District, Pa Co County, Hang Kia-Pa Co Nature Reserve, on calcareous outcrops in a deforested area, 24 February 2011,C. Gueidan1877 (BM—holotype). ITS barcode: KF959805. (Fig. 4A–C)

Thallus crustose, epilithic, determinate, matt, sometimes greyish-pruinose due to the presence of an epinecral layer, smooth, dark greyish brown to black, becoming slightly darker when wet, rimose-areolate, 0 10–0 25 mm thick, areoles 0 1–0 5 mm diam., often larger when fertile (0 5–1 0 mm). Upper cortexabsent to thin (<10mm) and weakly differentiated from the algal layer (pseudocortex, as defined in Gueidanet al. 2007), with hyaline to pale brown rounded cells (4–6mm diam.) and a thin (5–10mm) epinecral layer. Algal layer25–100mm thick, with a green Diplosphaera-like alga, eglobose, 6–8mm diam., single to clustered into Peritheciaimmersed in the thallus, 0 4–0 6 mm, one per areole, forming only slight pro-jections, with only the black ostiole visible at the thallus surface. Involucrellum black, ap-pressed to the excipulum wall and covering the upper part of the perithecium down to half the height to entirely covering the perithecium by fusing with the black basal layer, 50–150mm thick, contiguous with the excip-ulum to spreading laterally at the base (space between involucrellum and excipulum then filled with cells with thick melanized walls, 4–7mm diam.). Centrumeglobose, 250–300 mm diam. Excipulumdark brown to black, 10–25mm thick. Periphysespresent in ostiolar canal, pale brown, unbranched, sep-tate, 30–40 2–3mm. Pseudoparaphyseslining the upper part of the perithecial cavity, unbranched, septate, sometimes swollen at the apex, 20–45 1 5–3 0 mm. Interascal filamentsabsent at maturity, reduced to a

KI+ blue hymenial gel. Hymenial algal cells elongated to cylindrical (2 5–)3 5–7 0 (–8 0) (1 8–)2 0–2 5(–3 0) mm. Asci clavate, fissitunicate, 8-spored, 75–90 15–20mm. Ascosporescolourless to pale yellow, narrowly to broadly ellipsoid, muriform, (20–)22–28(–30) (9–)10–13(–15)mm.

Pycnidianot seen.

Etymology. The epithet fusca refers to the dark brown to black colour of the upper sur-face of this species.
Note. Two rather old perithecia from spec-imen CG1912 did not have hymenial algal cells.
Additional specimen examined. Vietnam:Hoa Bınh Province: Mai Chau District, Pa Co County, Hang Kia-Pa Co Nature Reserve, on calcareous rocks, 2011,C. Gueidan1912 (BM, VNMN).
Willeya laevigata Gueidan sp. nov.
MycoBank No.: MB807224
Differing from Willeya malayensisin having larger asco-mata and spores, a thicker thallus and an involucrellum closely appressed to the excipulum wall, as opposed to not appressed to the excipulum wall and laterally spread-ing.
Type: Vietnam, Hoa Bınh Province, Mai Chau District, Pa Co County, close to the limit with Son La Province, on shaded calcareous outcrops within the rain-forest, 25 February 2011, C. Gueidan1852 (BM—holotype). ITS barcode: KF959807. (Fig. 4D–F)
Thalluscrustose, semi-endolithic, deter-minate, matt,esmooth, greyish to brown-ish green, becoming olive-green when wet, continuous to rimose here and there, thick (0 15–0 60 mm). Upper cortexthin (5–15mm) and weakly differentiated from the algal layer (pseudocortex), with hyaline to pale brown rounded to angular cells (2–6mm diam.).Algal layer25–60mm thick, with a green Diplosphaera-like alga,eglobose, 4–8 mm diam., single or clustered in pairs,e organized in columns.Medullathick (250–
500 mm), endolithic, inspersed with rock crystals throughout, prosoplectenchymatous to paraplectenchymatous, with cells 5 0–7 5 mm diam. Basal carbonaceous layer absent. Prothallusnot apparent. Peritheciaentirely immersed in the thallus, not forming projections, large (c.0 6mm wide), with an ostiole visible on the thallus surface. Ostiole pale brown, sometimes sur-rounded by a black involucrellar ring. In older perithecia, an additional brown ring, resulting from the pigmentation of the upper part of the excipulum, can also be seen inside the black involucrellar ring. Involucrellum black, appressed to the excipulum wall and covering the upper part of the perithecium down to a third or half of its height, enlarging laterally at the lower extremities, inspersed with rock crystals, up to 200–300mm thick, scleroplectenchymatous, with melanized and thick-walled cells (7 5–10 0mm diam.).Cen-trum globose, 400–600mm diam. Excipulum pale, but becoming dark brown around the ostiole in older perithecia, 10–20mm thick. Periphyses present in ostiolar canal, pale brown, unbranched, septate, 25–40 2–3 mm. Pseudoparaphyseslining the upper part of the perithecial cavity, unbranched, septate, 40–50 1 5–3 0 mm.Interascal filaments absent at maturity, reduced to a KI+ blue hymenial gel.Hymenial algal cellselongated to cylindrical, sometimes in pairs or short filaments, 2 0–8 0 1 5–3 0mm.Asciclav-ate, fissitunicate, 8-spored, 90–100 20–30 mm.Ascosporescolourless to pale, narrowly to broadly ellipsoid, muriform, (20–)25–29(–31) 11–15mm. Pycnidianot seen.
Etymology. The epithet laevigata refers to the rather smooth appearance of the upper surface of this species.
Willeya protrudens Gueidan sp. nov.
MycoBank No.: MB807229. Differing from other species ofWilleyaby its perithecia characteristically forming projections.
Type: Vietnam, Tuyen Quang Province, Na Hang District, Na Hang Nature Reserve, on calcareous out-crops, 4 March 2011,C. Gueidan1945 (BM—holotype; VNMN—isotype). ITS barcode: KF959802 (Fig. 4G–I)
Thallus crustose epilithic, determinate, matt, smooth, greyish green to olive-brown, green to olive-green when wet, continuous to rimose at the periphery and rimose to sub-areolate at the centre. Irregular areoles and deeper cracks mostly found around the perithecia, with one perithecium per areole. Areoles 0 2–1 0 mm diam. Thallus thin at the margin (50–100mm), but thicker around the perithecia (200–300mm) due to the pres-ence of a black basal layer.Upper cortexthin (10–20 mm) and weakly differentiated from the algal layer (pseudocortex), with hyaline cells rounded to angular, 4–6mm diam. Algal layer 40–60mm thick, with a greenDiplo-sphaera-like alga,eglobose, 4–10mm diam., single or by pair, scattered throughout the algal layer. Medullaabsent. Black basal layer present at the centre of the thallus when perithecia densely aggregated, 200–250mm thick, possibly deriving from laterally spreading involuvrellae. Prothalluspale but becoming dark brown when contiguous with other lichen thalli. Perithecia protruding, entirely or only partly covered by the thallus, 0 3–0 8 mm, characteristically forming projections. Ostiole visible, brown, often surrounded by aelarge black involucrellar ring.Involucrellumblack, spreading laterally and not contiguous with the excipulum, 75–175 mm thick. Space be-tween involucrellum and excipulum filled with cells with thick melanized walls, cells 4–8mm diam.Centrumeglobose, 300–400 mm diam.Excipulumbrown to black, 10–25 mm thick. Periphysespresent in the ostiolar canal, pale brown, unbranched, septate, 30–40 2–3 mm. Pseudoparaphyses lining the upper part of the perithecial cavity, un-branched, septate, 25–100 2–3mm. Inter-ascal filamentsabsent at maturity, reduced to a KI+ blue hymenial gel.Hymenial algal cells elongated to cylindrical, sometimes in pairs or short filaments, (3–)4–9(–12) 1 5–3 0 mm. Asciclavate, fissitunicate, 8-spored, 60– 90 20–30mm. Ascosporescolourless to pale, narrowly to broadly ellipsoid, muriform, (20–)22–30(–32) (9–)10–14(–15)mm. Pycnidianot seen.
Etymology. The epithet protrudens refers to the projecting perithecia characteristic of this species.
Additional specimens examined. Vietnam: Tuyen Quang Province: Na Hang District, Na Hang Nature Reserve, Ban Bung village, on calcareous outcrops, 2011,C. Gueidan 1909 (BM); Na Hang Nature Reserve, near the lake after the dam, on calcareous outcrops, 2011,C. Gueidan 1940a, 1943, 1947 (BM). Hoa Bınh Province: Mai Chau District, PaCo County, Hang Kia-Pa Co Nature Reserve, on calcareous outcrops in small deforested valley, 2011, C. Gueidan1957a, 1957b, 1871 (BM), 1874, 1878 (VNMN). Ha Giang Province: BacMe District, Lac Nong County, on calcareous outcrops, 2011, C. Gueidan1885, 1922 (BM).

Refereces: The Lichenologist 46 (4): 515–533 (2014) British Lichen Society, 2014

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