Printer Friendly

FOUR NEW RECORDS OF THE GENUS PYRUS (ROSACEAE) FROM PAKISTAN.

Byline: M. Islam, H. Ahmad, J. Alam, H. Ali, M. Fahim and M. Hanif

Keywords: New Records, Pyrus (Pears), Rosaceae, Pakistan.

INTRODUCTION

Pyrus L. (pear group) belongs to the family Rosaceae and subfamily Rosoideae (Maleev, 1985; IAPT, 2012), while on the basis of molecular evaluation, Pyrus has been placed in subfamily Spiraeoideae by Potter et al. (2007) and Zheng et al. (2014). Internationally, members of this genus are mostly shrubs or trees and are pyramidal, umbrella or narrow-straight in shape (Cuizhi, 2003). Based on their geographical distribution, Pyrus has been divided in to two groups i.e. oriental and occidental pears (Bailey, 1917; Rubstov, 1944; Zhukovsky and Zeelinski, 1965). Approximately 12-15 species of oriental pears or Asian pears have been reported from China by Teng and Tanabe (2004) and 4 species are reported from Pakistan, mostely available in moist temperate region and rarely in sub tropical region (Islam et al., 2016).

Several cultivars of Pears belonging to Kashmir, Pakistan were evaluated for their fruits diversity, quality contolling traits and horticulture intrest by Ahmad et al. (2013) and Ahmad et al. (2017). Recently, diversity and production of pears were reported from northern Pakistan (Islam and Ahmad, 2018). On the other hand, 21 species of occidental pears have been reported, mostly from north Africa, Europe and Iran (Zamani et al., 2009, 2010, 2012, and 2016). On the bases of morphological and chemical characters, Pyrus has been grouped into, the East Asian Pea Pears, the larger fruited East Asian Pears, the North African Pears and the European and West Asian Pears (Challice and Westwood, 1973).

Speciation and origin in Pyrus had been taken place during the tertiary period in the mountainous areas of the western and southwestern China and spread both in east and West (Rubstov, 1944; Bell et al., 1996; Yamamoto and Chevreau, (2009) nearly all Asian pear species originated from five primitive genepools (Jiang et al., 2016). In East Asia, the commercial pear cultivars are sorted into five groups, among these, Ussurian pear and Chines sand pear have been originated from P. ussuriensis Maximowicz and P. pyrifolia (N. L. Burman), respectively (Teng and Tanabe, 2004). For commercial production, of these, only few species and more than 3000 cultivars have been developed (Pu and Wang, 1963 and Bell 1991). The commercilized species have been originated from a wild species P. pyrifolia Nakai (Kikuchi, 1948) in Asia, P. sinkiangensis T. T. Yu has been introduced as a commercial species (Peng and Iwahori, 2000).

Historically, the study area has been visited by a large number of invaders, visitors, traders and pilgrims etc. of different origins. Archeological remains, ruins, inscriptions and petroglyphs are scattered throughout the area. A brief historical sketch of the inhabitants of the area is Islam (799 A.D), Turkish Shahi (666-822 A.D) and Hindu Shahi (822-977A.D) (Ahmad, 2014). Besides cultural and other biological resources, these people had introduced a variety of crops into the area, some of which like the pears are still available in the traditional agricultural farmlands, kitchen gardens and field boundaries of the subsistence farms of the area and its fruits are used as solid, soft drinks and also used as root stock for grafting. Among these pear resources, only four species have been reported from different parts of Pakistan (Islam et al., 2016) while the remaining are unexplored and need exploration, evaluation and scientific identification.

Keeping in view, both the scientific and commercial importance of Pyrus resources, a scientific endeavor was undertaken for taxonomic exploration and characterization of the available diversity of Pyrus belonging to northern Pakistan. Review of the available literature shows that different authorities in different time reported number of species for the genus Pyrus (Rehder, 1915; Yu, 1963; Terpo and Franco, 1968; Temesy, 1969; Maleev, 1985 and Cuizhi, 2003). However, only two species, P. communis L. and P. pashia D. Don have been reported in the Flora of British India (Hooker, 1878). Later, these two species and P. lindleyi Rehder were also reported by Stewart, (1972). In the near past, four species viz., P. pashia D. Don, P. calleryana Decaisne, P. bretschneideri Rehder and P. pyrifolia Nakai have been reported from Pakistan (Islam et al., 2016).

Beside these, large number of undocumented and unidentified wild and cultivated species, varieties and cultivars of Pyrus are available in the temperate region of Pakistan. However, the genus Pyrus and its associated species belonging to the occidental pears are not genetically tagged nor taxonomically reported for the Flora of Pakistan (Landrein et al., 2009). The objective of the present work is to describe and provide the detailed morphological characters of species belonging to the occidental pears, reported as new records for the Flora of Pakistan.

MATERIALS AND METHODS

The plant materials of the current research work were collected during 2010-2011 from various locations of District Swat and Mansehra, Khyber Pakhtunkhwa, Pakistan (Fig. 01). The specimens were collected in flowering, fruiting and in med sessions. The relevent field information such as collection numbers, date of collection, location, name of the collector, tagging and geographical coordinates of each specimen were recorded at the spot. The specimens were processed and pasted on the herberium sheets. Specimens were checked and identified with the help of field notebook, photographs and to the relevent literatue of Rehder (1915); Maleev (1985); Yu (1963); Temesy (1969); Terpo and Franco (1968); Hooker (1878); Kalkman (1998); Nakai (1926) and Cuizhi (2003). The voucher specimens and duplicate specimens have been deposited in the Herbarium Hazara University (HUP), Mansehra, KP, Pakistan.

Diagnostic key to the Species

Key to the Species

1 + Pome without persistent sepals, rarely few persistent

Pome present and style 2-5 in number........................2

- Pome with persistent sepals and style 3-5 in number.....6

2 + Leaf margin spiny serrate....................................3

- Leaf margin non-spiny serrate................................4

3 + Pome yellow; leaf basally cuneate.............................. ...............4. P. bretschneideri

- Pome brown; Leaf basally sub-cordate or rounded...................................................................3. P. pyrifolia

4 + Leaf margin sharply serrate.............5. P. phaeocarpa

- Leaf margin obtusely serrate............................... 5

5 + Leaves are corymb glabrous; stamens 20 and styles 2 or 3...............................................2. P. calleryana

- Leaves and corymb initially pubescent; stamens 25-30 and styles 3-5.......................................1. P. pashia

6 + Leaf margin spiny serrate....................................7

- Leaf margin serrulate or obtusely serrate and without spins......................................................................... 8

7 + Leaf blade long spiny-serrate; styles 5; pome yellow...........................................7.P. ussuriensis

- Leaf blade short spiny-serrate; styles 4; pome brown....................................................9. P. hopeiensis

8 + Leaf margin serrate......................................... 9

- Leaf margin seteso or obtusely serrate.....................10

9 + Pome yellowish green, ovoid or obovoid, 5-loculed; fruiting pedicel 4-5 cm and thickened distally........................10. P. sinkiangensis

- Pome brown sub-globose or obovoid, 3-4 loculed; fruiting pedicel 3-4 cm and not Thickened distally................................8. P. serrulata

10 + Leaf margin seteso serrate................11. P. ovoidea

- Leaf margin seteso or obtusely serrate....................11

11 + Fruit thick-skinned and with numerous grit cells..........................................12. P. turcomanica

- Fruit not as above............................................ 12

12 + Pome yellowish green.....................................13

- Pome brown....................................................14

13 + Pome 1.5-2.5 cm in diam; 5-7 flowers; stamens 25 styles 3-4.....................................6. P. pseudopashia

- Pome 1-1.5 cm in diam; 3-6 flowers; stamens 25; styles 5(4)..............................................13. P. xerophila

14 + Pome obovoid or sub-globose; leaf blade elliptic to ovoite; petiole thin, 1.5-5 cm long.........14. P. communis

- Pome depressed globose; leaf blade broadly ovate to suborbicular; petiole thick, 2-3 cm long.......................................15. P. armeniacifolia

Table 1. Main morphological differences among four new Pyrus records.

Characters###P. ussuriensis###P. armeniacifolia###P. hopeiensis###P. communis

Tree height###10-15 m###8-12 m###6-8 m###5-15 m

Leaf blade###ovate to broadly ovate###wide ovate###Ovate or sub###Ovate or sub-rounded to

###orbicular###elliptic

Leaf base###rounded or sub-cordate###rounded and ending###rounded or sub-###broadly cuneate to sub-

###suddenly###cordate###rounded

Leaf margin###long spinulose serrate###crenulate-serrate or near###shortly spinulose-###obtusely serrate, serrulate,

###to dentate###serrate###cuneate,

Inflorescence###5-7 flowered###8-10 flowered###6-8 flowered###5-9 flowered

Stamens###20, shorter than petals###18-20,###20, less than A1/2 of the###20, same level

###A1/2 of the petals###petals

Fruit###Sub-globose###depressed-globose###globose or ovoid###oblong, pyriform, obovoid,

Fruit color###Yellow###Green###brown###Green

Table 02. Comparison of new records of Pyrus with previously reported species of Pyrus.

Characters###New Records of Pyrus###Previously reported species of Pyrus

###P.###P.###P.###P.###P. pashia###P.###P.###P. pyrifolia

###ussuriensis###armeniacifolia###hopeiensis###communis###calleryana###bretschneideri

Tree Height###10-15 m###8-12 m###6-8 m###5-15 m###5-12 m###5-8 m###5-8 m###7-20 m

Leaf margin###long###crenulate-###shortly###obtusely###obtusely###initially###spinulose-###spinulose-

###spinulose###serrate or near###spinulose-###serrate,###serrate###glandular###serrate###serrate

###serrate###to dentate###serrate###serrulate,###serrate

###cuneate

Inflorescence###5-7###8-10 flowered###6-8###5-9###6-10###6-12###7-10 flowers###6-9

###flowered###flowered###flowered###flowered###flowered###flowered

Stamens###20 shorter###18-20,###20, less###20, same###27-31###20 slightly###20 A1/2 of the###20 or 23-25

###than petals###A1/2 of the petals###than A1/2 of###level###slightly###shorter than###petals###as long as

###the petals###shorter###petals###petals

###than

###petals

Fruit###Sub-###depressed-###globose or###oblong,###Sub-###globose###globose-ovoid,###Sub-

###globose###globose###ovoid###pyriform,###globose###globose

###obovoid

RESULTS AND DISCUSSION

The present research work comprised of comprehensive morphological description, citations, synonyms, data of the examined specimens, vernacular name and distribution of each of the four new records of the genus Pyrus (Rosaceae) viz. P. ussuriensis Maximowicz, P. armeniacifolia T.T. Yu, P. hopeienses T.T. Yu, P. communis L. and their details are presented here.

1. Pyrus ussuriensis Maximowicz, Bull. Acad. Imp. Sci. Saint-Petersbourg, Ser. 2, 15: 132. 1856; Proc. Amr. Acad. Arts and Sci. 50: 227. 1915; Fl. of U. S. S. R. 9: 265. 1985; Cuizhi, Fl. China. 9: 174. 2003.

Pyrus communis Bunge, Enumer. Plantarum, quas in China boreali collegit anno, 1833. Pyrus sinensis Decaisne, Jard. Fruit. I. t. 5. (1872); Pyrus simonii Carrier in Rev. Hot. 28. 1872. Tree 10-15 m tall, small young branches yellowish gray to purplish brown, mature branches yellowish gray to yellowish brown, Stipule caduceus, linear lanceolate, apex acuminate, young petiole densely hairy, soon hairless; leaf blade ovate to broadly ovate, glabrous or thickly hairy when young, soon glabrescent, base rounded or sub-cordate or sometime cordate, lustrous green above, margin long spinulose serrate, apex shortly acuminate or long tapering acute apex. Hypanthium campanulate, abaxially hairless or rarely tomentose. Inflorescence corymb, 5-7 flowered; peduncle tomentose in young condition, quickly hairless; Hypanthium campanulate, abaxially hairless or rarely tomentose.

Sepals triangular-lanceolate, sparsely pubescent above and adaxially tomentose, margin initially glandular, denticulate, apex acuminate. Petals white, obovate or broadly ovate and glabrous. Stamens 20, shorter than petals. Ovary 5 loculed, 2 ovules per locule. Styles 5, same level with stamens. Fruit, pome, yellow, sub-globose and sepals persistent. Fruit become reddish in color and less tasty. Fl. April. Fr. Aug-Oct.

Distribution: China, Russia, Korea and Pakistan.

Specimens examined: Pakistan, B-7 Swat Dist. Kuz Shawar 34Adeg 40. 014'N and 72Adeg 19. 621' E, 4850 ft., 20.6.2010, M. Islam 47 (HUP); Kuz Shawar 34Adeg 40. 014'N and 72Adeg 19. 621' E, 4850 ft., 12.4.2011, M. Islam 91 (HUP).

Vernacular name: Mamothay (Pashto).

2. Pyrus armeniacifolia T. T. Yu, Pl. XXVII, 2; Yu. Acta Phytotax. Sin. 8: 231. 1963; Cuizhi, Fl. of China 9: 176. 2003.

Tree pyramidal, 8-12 m; branches slightly angular, purple-dark brown lenticels, glabrous; young branches outside wavy with fairly long soft straight hairs except glabrous. Leaves wide ovate or sub orbicular, thick, 4-5 cm long and wide, acute and obtuse, base rounded and ending suddenly, margin crenulate-serrate or near to dentate, on the upper side dark green, glabrous. petioles 2-3 cm. long, glabrus. Inflorescence, umbel-raceme, 8-10 flowered, pedicel initially tomentose, become glabrous. Hypanthium bell shaped. Sepals triangular, apex acute, white wooly hairs on both sides. Petals white, narrow at the base, lobed-rounded above. Stamens 18-20, in single circle, A1/2 of the petals. Styles 5 (or 4), pome depressed-globose, green, 3-4 in group, calyx persistent crown, sepals ovate oblong with pome, 5-locules; similar to P. xerophila Yu, but the fruits of P. armeniacifolia are depressed globose, leaves sub orbicular or almost orbicular or broadly ovate; fruit depressed-globose.

Distribution: Pakistan, China (N. Xinjiang).

Specimens examined: Pakistan, B-7 Mansehra Dist. Balakot-Sangar, 34Adeg, 34. 986' N and 073Adeg, 22. 201' E, 5505 ft., 3.4.2011, M. Islam 66 (HUP); Balakot-Sangar, 34Adeg, 34. 621' N and 073Adeg, 22. 818' E, 5505 ft., 28.3.2010, M. Islam 51 (HUP); Balakot-Sangar, 34Adeg, 34. 62' N and 073Adeg, 22. 812' E, 5505 ft., 28.3.2010, M. Islam 12-B (HUP).

Vernacular name: Atti Batang (Hindko), Qualperang Tango (Pashto).

3. Pyrus hopeiensis T.T. Yu, Acta Phytotax. Sin. 8: 232. 1963; Cuizhi, Fl. of China 9: 174. 2003.

Trees 6-8 m tall. Branchlets dark purple or purplish brown, branches are flexible and have capacity to bear load: Stipules caduceus, linear-lanceolate, petiole 2-4.5 cm, sparsely pubescent or glabrous; leaf blade ovate, or sub orbicular, glabrous, base rounded or subcordate, margin shortly spinulose-serrate, apex long or shortly acuminate. Inflorescence raceme umbel-like, 6-8 flowered; peduncle subglabrous; peduncle subglabrous; Pedicel 1.2-1.5 cm long, abaxially thickly tomentose and sparsely pubescent. Flower 2.5-3 cm in diam. Hypanthium copular or plate like, sub glabrous. Sepals triangular-ovate, elongated, abaxially sparsely pubescent, adaxially densely pubescent, margins denticulate, apex acuminate. Petals white, elliptic-obovate, ca 8x6 mm, narrow and shortly clawed at base. Stamens 20, (rarely 17-19) less than A1/2 as long as petals, filament white while anthers are pinkish, bending to the center.

Ovary 4 or 5-loculed, with 2 ovules per locus; styles 5 (or 4), nearly as long as stamens, glabrous, sometime three short and two long. Pome brown, spotted, globose or ovoid, 4 (or 5)-loculed; fruiting pedicel 1.5-3 cm, glabrous; sepals persistent. Fl. Apr, fr. Aug-Sep.

Specimens examined: Pakistan, B-7 Swat Dist. Malawooch, Kuz Shawar, 35Adeg 50. 045'N and 72Adeg 19.561' E, 4855 ft., 17.6.2010, M. Islam 44 (HUP); Malawooch, Kuz Shawar, 35Adeg 56. 341'N and 72Adeg 20.782' E, 5300 ft., 11.4.2011, M. Islam 44 (HUP).

Vernacular name: Pykhawary Tango (Pashto)

4. Pyrus communis L. Sp. pl. 479, 1200. 1753; Prodr. 2: 643. 1825; Fl. Ind. Ed. 2, 2: 391-394. 1832; Decaisne, Jard. Fruit. 1: 340, pl.1. 1872-74; Rehder, Man., ed. 2: 403. 1940; Terpo and Franco, Fl. Europaea 2: 66. 1968; Fl. Brit. Ind. 2: 374. 1978; Maleev, Fl. USSR. 9: 261. 1985; Cuizhi, G., Fl. China 9: 175. 2003.

Trees 5-15 m tall, branchlets grayish brown to dark brownish, sometime with or without spines, rising on young. young twigs stout, reddish-brown, soon becoming glabrous and shining. Stipules non-persistent, linear lanceolate; Petiole 1.5-5 cm. slender, slightly pubescent when young, soon glabrescent; Leaf blade ovate or sub-rounded to elliptic, 2-5 (7)x 1.502.5 cm, young pubescent, soon abaxially pubescent along midvein, base broadly cuneate to sub-rounded, margin obtusely serrate, serrulate, cuneate, crenate, rarely entire, apex acute or shortly acuminate, lustrous green above and light green below. Inflorescences, raceme umbel like, corymb, 5-9 flowered, 2.5-3.0 cm across; Peduncle glabrous or subglabrous; Pedicel 2-3.5 cm, white hairy, subglabrous and become glabrous at maturity. Flowers 2.5-3 cm in diam. Hypanthium bell shaped, Calyx persistent, Sepals triangular-lanceolate, both surfaces pubescent, margin sparsely glandular denticulate when young, apex acuminate.

Petals white or pink, obovate, 1.3-1.5x 1x1.3 cm, base, 3-5 x 1.5-2 cm, base narrow, shortly clawed, suborbicular or obovate, spreading, glabrous. Stamens 20, filament white, same level when mature. Ovary 5-loculed, style 5 (or 4) nearly as long as stamens, pubescent basally. Fruit, pome, oblong, pyriform, obovoid or sub-globose, 5-loculed, green or yellow when ripe, rarely reddish, dotted; sepals persistent. Fl. Apr., fr. Jul-Aug.

Distribution: China, Bhutan, Vietnam; South Asia, Europe, North Iran, Central Asia, Central and South Europe, Turkey, Russia, Pakistan, Afghanistan and India.

Specimens examined: Pakistan, B-7 Swat Dist. Madyan, Chail, 35Adeg 08. 192' N and 72Adeg, 32.960' E, 5149 ft., 19.4.2010, M. Islam 22-A (HUP); Kuz Shawar, 34Adeg 49.025' N and 72Adeg 18. 680' E, 4818 ft. 19.4.2010, M. Islam 20 (HUP); Kuz Shawar, 34Adeg 59.068' N and 72Adeg 18. 609' E, 4785 ft. 18.4.2010, M. Islam 18 (HUP); Kuz Shawar, 34Adeg 59.064' N and 72Adeg 18. 654' E, 4788 ft. 12.4.2011, M. Islam 92 (HUP); B-7 Mansehra Dist. Batal, 34Adeg 32.927' N and 73Adeg 08.749' E, 4540 ft., M. Islam 36-C (HUP); Batal, 34Adeg 32.946' N and 73Adeg 08.758' E, 4541 ft., 23.5.2010, M. Islam 34-A (HUP); Batal, 34Adeg 32.343' N and 73Adeg 08.622' E, 4280 ft., 23.5.2010, M. Islam 34 (HUP); Balakot, Sanger, 34Adeg 34.700' N and 73Adeg 22.396' E, 5200 ft., 03.4.2011, M. Islam 72 (HUP).

Vernacular name: Pear (English), Bagugosha (Kashmir), China Batang (Hindko), Neshpati (Urdu and Pashto). Several taxa of the genus Pyrus have been reported from 53 countries around the world by Postman (2008), among these, 22-26 are widely recognized primary species, (Bailey, 1917). From different geographical regions and countries of the world, different taxa of Pyrus have been reported by different authorities. Among these, 12 species have been reported by Temesy (1969), 15 species have been reported by Cuizhi (2003) and 24 species have been reported in different time by Zamani et al. (2009; 2010; 2012 and 2016) for the flora of Iran. Most of these species are not yet reported from Pakistan except P. pashia which is common for both the countries, (Zamani et al., 2009 and Islam et al., 2016), 14 species have been reported by Islam (2015).

Moreover, in present work, most of the taxa belonging to Pyrus were described and evaluated with the help of flora of China (Cuizhi, 2003) as new records for the flora of Pakistan. Similarly, the original description of different species of Pyrus, (Rehder, 1915) are fruitful for description and evaluation of P. ussuriensis and P. communis. Pyrus armeniacifolia and P. hopeiensis are the two among the six species which were for the first time reported from China (Yu, 1963). Pyrus ussuriensis and P. communis were reported for the flora of USSR (Maleev, 1985). Similarly, 4 species have been reported by Hooker (1878). Further (Stewart, 1972) enlisted the name of the 2 species of Pyrus without description and detail records, in the annotated catalogue of the vascular plants of West Pakistan and Kashmir. However (Islam et al., 2016) reported 4 species of Pyrus viz. P. pashia, P. calleryana, P. bretschneideri and P. pyrifolia as new records from Pakistan.

Conclusion: Northern parts of Pakistan are rich sources of plant biodiversity. The area possesses diverse types of Pyrus taxa, which are neither genetically tagged nor taxonomically identified. In the present work, four new records of the genus Pyrus i.e P. ussuriensis, P. armeniacifolia, P. hopeiensis and P. communis are reported here and would contribute to the flora of Pakistan specifically and overall update the knowledge with respect to Pyrus.

REFERENCES

Ahmad, M., M.A. Anjum and Y. Teng (2013). Pyrus germplasm of Kashmir-Pakistan. Present status of pears in Azad Jammu and Kashmir and current research with reference to their nutritional values. LAP Lambert Academic Publisher, Pp. 1-84, ISBN. 3659422576.

Ahmad, M., M.A. Anjum, S. Hussain, S. Ejaz, S. Ahmad and S. Erisli (2017). Biodiversity in Indegenous Germplasm of Pyrus from Pakistan based on phonotypical and morphological traits. Erwerbs-Obstbau. 59(1): 19-27.

Ahmad, M. (2014). Ancient Pakistan-An Archeological History.ISBN.13: 978 1495966439

Bailey, L.H. (1917). Pyrus, In. Standard Encyclopedia of horticulture, V. Published by Macmillan, New York.

Bell, R.L. (1991). Pears (Pyrus). in. J. N. Moore and J. R. Ballington Jr. (Eds.), Genetic Resources of Temperate Fruit and Nut Crops, 2: 655-697. DOI: 10.17660/Acta. Hort.1991.290.15.

Bell, R.L. (1996). Pears (Pyrus) In: Moore J. N., Ballington, J. R. (eds.) Genetic Resources of Temperate Fruit and Nut Crops II. International Society for Horticultural Science, Acta. Hort. 290: 657-697.

Bell, R.L., H.A. Quamme, R.E.C. Layne and R.M. Skirvin (1996). Pears. In: J. Janick and J. N. Moore (eds.), Fruits Breeding. Tree and Tropical Fruits. I: 441-514. Published by Wiley. ISBN. 047131014X.

Bunge, A. (1833). Pyrus communis.-In: Enumeratio Plantarum, quas in China boreali collegit anno. P. 101.

Challice, J.S. and M.N. Westwood (1973). Numerical Taxonomic studies of the genus Pyrus using both chemical and botanical characters. Bot. J. Linn. Soc. 67(2): 80-83.

Cuizhi, G. (2003). The Genus Pyrus. - In: Zhengyi, W., H. R. Peter and H. Deyuan (eds.), Flora of China. 9: 46-434.

Hooker, J.D. (1878). Family Rosaceae, The Genus Pyrus. Fl. Brit. Ind. 2: 387-404

Islam, M. (2015). Phenotypic and molecular characterization of the land races of pears cultivated in northern Pakistan. Ph. D Thesis (unpublished). Department of Botany, Hazara University, Mansehra, KP, Pakistan. Pp.51-81. http://hec.gov.pk/english/services/students/PCD/Pages/Directory.aspx

Islam, M., H. Ahmad, H. Ali and J. Alam (2016). New records of the genus Pyrus (Rosaceae) from Pakistan and Azad Kashimir. Iran. J. Bot. 22(2): 82-87.

Islam, M. and H. Ahmad (2018). Pears (Pyrus) of Northern Pakistan. Edited in: Crop Production Technologies for sustainable use and conservation. Physiological and Molecular Advances. Published by Apple Academic Press. ISBN: 9781771887267.

IAPT. (2012). International Association for Plant Taxonomy.(http://www.iapt-taxon.org/nomen/main.php?page=art19

Jiang, S., X. Zheng, P. Yu, X. Yue, M. Ahmed, D. Cai, T. Yuanwen (2016). Primitive Genepools of Asian Pears and Their Complex Hybrid Origins Inferred from Fluorescent Sequence-Specific Amplification Polymorphism (SSAP) Markers Based on LTR Retrotransposons. PLoS ONE 11(2): e0149192. doi: 10. 1371/

Kalkman, C. (1988). The Phylogeny of the Rosaceae. Bot. J. Linnean Soc. 98 (1): 37-59.

Kalkman, C. (1998). Rosaceae, Pyrus. P. 379.

Kikuchi, A. (1948). In: Horticulture of fruit trees, 1, Yokendo, Tokyo. P. 64-121.

Landrein, S., R. Borosova, J. osborne, M. Shah, M.T.M. Rajput, S. S. Tahir and J. Zielinski. (2009). Rosaceae (I)-Potentilleae and Roseae. In: Ali, S. I. and Qaiser, M. (eds.). Flora of Pakistan.

Maleev, V.P. (1985). The Genus Pyrus L. Flora of U. S. S. R. 9: 259.

Nakai, T. (1926). Notulae ad Plantas Japoniae and Koreae xxxiii. The Botanical Magazine. XL(479): 564-566.

Peng, S. and S. Iwahori (2000). Variety, distribution and major cultivars of domesticated Pyrus spp. in China. Agric. Hort. 75(2): 763-772.

Postman, J.D. (2008). World Pyrus Collection at USDA GenBank in Corvallis, Oregon. Acta Hort. Proc., Xth Int. Symp. on Pear. Pp. 527-535.

Potter, D., T. Eriksson, R.C. Evans, S. Oh, J.E.E. Smedmark, D.R. Morgan, M. Kerr, K.R. Robertson, M. Arsenault, T.A. Dickinson and C.S. Cambell (2007). Phylogeny and Classification of Rosaceae. Pl. Syst. and Evol. 266(1-2): 05-43.

Pu, F. and Y. Wang (1963). Pomology of China. 3. Pears (in Chinese). Shanghai Sci.

Rehder, (1915). The Chinese species of Pyrus. Proc. Amer. Acad. Arts. Sci. 50: 227-241

Rubstov, G.A. (1944). Geographical distribution of the genus Pyrus and trends and factors in its evolution. Am. Nat. 78 (777): 358-366.

Stewart, R.R. (1972). An Annotated Catalogue of the Vascular Plants of West Pakistan and Kashmir. - In: Nasir, E. and Ali, S. I. (eds.). Flora of West Pakistan-Karachi. P. 364.

Temesy, S.E. (1969). Rosaceae-Pyrus L., In Rechinger, K.H. (ed.), Flora Iranica. 66: 27-36.

Teng, Y. and K. Tanabe (2004). Reconsideration on the origin of cultivated pears native to East Asia. Acta. Hort. 634: 175-182.

Terpo, A and J.A. Franco (1968). The genus Pyrus, Family Rosaceae. - In: Tutin, T. G., Heywood, Burger, N. A., Moore, D. M., Valentine, D. H., Walters, S. M., and Webb, D. A. (eds.), Flora Europaea 2: 65-66.

Yamamoto, T. and E. Chevreau (2009). Pear genomics, In: Folta, K. M. and Gardiner, S. E. (eds.), Genetics and Genomics of Rosaceae, Springer New York. 6: 163-186.

Yu, T.T., (1963). Acta. Phytotax. Sin 8: 233-234.

Zamani, A. and F. Attar (2010). Pyrus longipedicellata sp. nov. (Rosaceae) from central Alborz, Iran. Nord. J. Bot. 28(4): 484-486.

Zamani, A., F. Attar and H. Maroofi (2012). A synopsis of the genus Pyrus (Rosaceae) Nord. J. Bot. 30(3): 310-332.

Zamani, A., F. Attar and M. R. Joharchi (2009). Pyrus pashia (Rosaceae): a new record for the flora of Iran. Iran. J. Bot. 15 (1): 72-75.

Zamani, A., F. Attar, L. Civeyrel and J. A. Akopian (2016). Pyrus cordifolia sp. nov. and two new records of Pyrus (Rosaceae) from Iran. Nord. J. Bot. 34(6): 001-005.

Zheng, X., D. Caj, D. Potter, J. Postman, J. Liu and Y. Teng (2014). Phylogeny and evolutionary history of Pyrus L. revealed by phylogenetic trees and networks based on data from multiple DNA sequences. Mol. Phylogenet. Evol. 80: 54-65.

Zhukovsky, P.M. and Q.B. Zeelinski (1965). Main gene centres of cultivated plants and their wild relatives within the territory of the USSR. Euphytica. 14(2): 177-188.
COPYRIGHT 2019 Knowledge Bylanes
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2019 Gale, Cengage Learning. All rights reserved.

Article Details
Printer friendly Cite/link Email Feedback
Publication:Journal of Animal and Plant Sciences
Geographic Code:9PAKI
Date:Apr 23, 2019
Words:4477
Previous Article:QUANTITATIVE AND QUALITATIVE RESPONSE OF WHEAT TO PSEUDOMONAS FLUORESCENS RHIZOBACTERIA APPLICATION.
Next Article:RESPONSE OF SPRING WHEAT ON AGRICULTURAL MEASURES IN THE REGION WITH LOW RAINFALL.

Terms of use | Privacy policy | Copyright © 2021 Farlex, Inc. | Feedback | For webmasters |