Advances breeding of Pear
- 1. PearBreeding 1 Speaker by Gangaram Rana Ph.D scholars . Dept. Fruit Sciences IGKV,RAIPUR
- 2. Introduction- • Botanical name:- • Pyrus communis (European pear) • Pyrus pyrifolia (Asian pear) • Genus: Pyrus Subfamily: Pomoideae • Family: Rosaceae • Origin – Western China • Inflorescence – Coryms, Fruit type- Pome • Basic chromosome No.: 17 • Genome size -512Mb China (2012) • Chilling requirement :- 1200 hrs. • Introduces in India by 19th century in Partharnakh (Punjab) • Pear fruits are consumed fresh, canned, as juice and dried. • Low chilling varieties is cultivation in sub –tropical region of UP, PB, UK and HR.
- 3. Domestication- During the 19th century, Belgium developed varieties “Beurre Bosc,” “Beurre d’Anjou,” “Flemish Beauty,” and “Winter Nelis” . In Asia, the cultivation began over 2500 years ago, with the main species Pyrus pyrifolia, Pyrus serotina, and Pyrus ussuriensis. During the Edo period in Japan (1603–1868) over 150 cultivars were documented. Pear was introduced by the English and French settlers in the United States and Canada, and in 1629, there was record of its cultivation in New England In the United States, 19th century, breeders (crosses between Asian and European pears) to resistance to cold and “fire blight” disease.
- 4. Genetic resources- • World’s largest pear germplasm about 1700 accessions representing 26 major Pyrus taxa and their hybrids are being maintained at USDA National Clonal germplasm in Corvallis, USA. • 750 pear collected and deposited at Kobe University in an ex situ field gene bank. • In India, 97 accessions of pear germplasm is being maintained in NBPGR . • 56 accessions at Regional Horticulture Station, Kotkhai. • Other like IARI, Regional Station, Amartara, Shimla also maintaining the germplasm of some improved types. • South the Nilgiri hills also temperate fruits eg. apple, pear, peach, apricot, plum, walnut, almond, pecan nut, hazelnut, chestnut, berries.
- 5. Centre of diversity: The genus Pyrus has probably originated in the mountainous regions of western china. Vavilov proposed 3 centres of origin for the cultivated pears Chinese centre Central Asiatic centre Near eastern centre The important species originated in the Chinese centre are P.pyrifolia ,P.ussuriensis, P.betulifolia. The indigenous species of central Asiatic centre are P.communis, P.salicifolia,P.regeli,and P.pashia. Sub tropical regions cultivation of many low chilling cultivars such as patharnakh, leconte, keiffer and Chinese sandy pear has been reported even from the hot plains of northern India.
- 6. Origin and distribution Probably originated in the mountainous regions of western China where from it moved both in east and west directions. • Vavilov (1951) proposed 3 centres of origin for the cultivated pears 1. Chinese centre 2. Central Asiatic centre 3. Near Eastern centre/Asia minor Salient features of very important species are given below: 1) P. Communis (European pear) Trees are paramedical in shape, medium tall and spiny when young.
- 7. 2) P. pyrifolia (Sand pear) Tree is tall, vigorous & spreading type. Fruits are mostly round (apple shaped) & very hard. 3) P. pashia (Wild Himalayan pear) Locally known as ‘Mehal’, ‘Kainth’ or ‘Shaira’.Mainly used as rootsock in India. 4) Pyrus nivalis Jacq (French snow pear):- Distribution is mainly in Australia and wild in France.The plant is very colourful, small with thick shoots
- 8. Species • Zeven and Zhukovsky (1975) mentioned about 60 species, among them 22 primary species and the rest are non- primary species which may be botanical varieties, subspecies or interspecific hybrids. • Bell and Hough (1986) classified all the primary species into 5 groups on the basis of geographical distribution as under:
- 9. 1.Europian group P . communis, P . nivalis, P . cordata, P . caucasica. 2. North Africa group P .longipes, P .gharbiana, P .memorensis. 3. West Asiangroup P . syriaca, P . elaeagrifolia, P . amygdaliformis, P . salicifolia, P .glabra, P . regelii. 4. East Asian group P .pyrifolia, P .kansuensis, P . ussuriensis, P . hodoensis. 5. Asian group P . calleryana, P . betulifolia, P . fauriei, P . dimorphophylla, P .koehnei.
- 10. FLORAL BIOLOGY, ANTHESIS AND POLLINATION: Flowers are hermaphrodite. It bears flowers on the 2 year- old wood. Chilling requirement: - 1200 hrs. below 7°c temp. Anthesis vary with different cultivars and depending on climatic conditions. Maximum opening of the flowers is between 6.00am – 6.00pm with gradual increase upto 12.00pm. The flower borne from terminal, mixed buds of short spurs, appearing before or with the leaves. Flower corymbose inflorescences, 5-7.5 cm wide, containing 5-7 showy white, 2.5-3.5 cm wide flower and protogynous. Each flower has 5-6 petals, 20-30 pink, red or purple anthers with 2 to 5 free style.
- 13. Pollination Mostly self-incompatible pollinated by insects especially bees. 1. Pears are self-sterile and need more than one variety planted within 12 or 15 m of each other in order to cross-pollinate. 2. It flowers around MarchApril, while fruiting occurs in July- September.
- 14. Pollination requirements and flower structure: more ovaries require more visits *One visit may be adequate if the female parts are receptive, thepollen viable, and the varieties compatible. single ovary pollen
- 17. Fruit quality Fruit quality is another very important objective in all pear breeding programmes.it includes size, shape, skin colour, flesh colour, texture, flavour, storage life and processing quality of fruits. Cultivars having bright yellow with a bright red blush fruit colour on ripening is required. Cultivars with good flavour with high sugar and aromatic compounds and less tannin and acid contents. Long storage life without internal breakdown is another important. Resistance of insect pest and disease Cultivars resistant to fire blight disease or Psylla pest are to be evolved. Scion and Rootstock To develop dwarf scion and dwarf rootstocks tolerant to wet and saline salts and resistant to diseases like Ganoderma and root rot. Cultivars resistant to cold, high temperatures, wet or drought conditions are also need to be evolved. Develop high yielding cultivar which has to be precocious, annual bearer, and more productive per unit of land. Objective of pear breeding
- 18. Problems in breeding • It is normally a cross pollinated crop, hence highly heterozygous in nature. • Long juvenile phase. • The phenomenon of vegetative parthenocarpy. • Excessive fruit drop, susceptible to different biotic and abiotic stress. • In dwarfing rootstock narrow genetic base for dwarfing character within the genus Pyrus.
- 19. Rootstocks breeding- • Europe continues to rely heavily on quince rootstocks for high density planting systems, except in areas of high soil pH.. • Fire blight resistant types have been found in progeny of the P. communis cross, 'Old Home' x 'Farmingdale' (OH F1 rootstock series) • Other dwarfing P. communis rootstocks include 'Pyrodwarf' and 'BU 2-33' coming from 'Old Home' x 'Bonne Louise d'Avranches' (Jacob 1998 and 2002) • Pyrus pashia is used in northern India and southern China; it is resistant to black end, although it is sensitive to lime-induced chlorosis and is susceptible to the woolly pear aphid (Bell et al. 1996).
- 20. INTRODUCTION: Bartlett, Anjou, Kieffer are only introductions from Europe and are well acclimatized to the northern and southern Indian hills. Bartlett Anjou Kieffer
- 21. CLONAL SELECTION: • An extensive survey of pear growing areas in Punjab and PAU, Ludhiana resulted in the identification of 19 superior strains of soft pears. • Soft fleshed selections Red Blush, Punjab Gold, and Punjab Nectar are promising. • Red Blush with high yield potential. Punjab nectar is also a high yielder and very juicy. • Punjab gold has large fruits and good quality. • Variation in the renowned cultivar is often observed which may be due to gene mutation.
- 22. Pear Quince Intergenic sterile hybrid Mule Troth early pach X wild goose plum Kamdesa Peach x sand cherry Pyronia Pear x quince Unique Quince x pear 2.HYBRIDIZATION: • Intraspecific, interspecific and intergeneric hybridisation are possible in pears because no major crossing barrier exists. Prabhat (sarbati x florida sun ) • Wild seedlings are employed as better sources of disease resistance or cold hardiness back crossing. • Bartlett is a interspecific hybrid variety. • Kiffer is a hybrid between French pear and oriental pear.
- 23. MUTATION: • When the improvement skin colour, disease resitance,compact growth, self- fertility and maturity season, mutation either through ionizing radiation or chemical mutagenic agents . • One of them, 'Gold Nijisseiki', black spot resistant varieties show high promise (Ahloowalia et al. 2004). • Max red bartlett is bud mutation of bartlett • Mutation induction may be useful in breaking up linked genes and creating genetic variability but it is no substitute for conventional systems of selection and hybridisation. • Spontaneous mutations (bud sports) have given red coloured cultivars eg. Starkimson from clapp’s and Red Anjou from Anjou.
- 24. Molecular breeding- • The organoleptical test of leaf tissue of greenhouse and field grown plants demonstrated taste modification. For plant protection against fungal and microbial attack, the plant defensins genes (PD) have been transferred to pear. • PD gene from Raphanus sativus was transferred to pear variety Burakovka by using different agrobacterial vector systems. • The bar gene cloned in the “Bioengineering Center” RAS has been used in our research for obtaining phosphinotricine (PPT)-resistant pear clonal rootstocks • Some of them were resistant to herbicide Basta treatment equivalent for 24 1/ha. (Source- International Symposium on Asian Pears, Commemorating the 100th Anniversary of Nijisseiki Pear)
- 25. Fruit quality • Deep red colored sports of 'Bartlett' called 'Cardinal Red' and 'Max Red' were found to be regulated by a single dominant gene, C by Zielinski (1963). Brown (1966) • In 'Bartlett', 77 volatile compounds have been identified with varying impacts on flavor (Jennings and Tressel 1974). • The size of pears is under polygenic control with variable levels of heritability depending on breeding population (Zielinski et al. 1965). • The inheritance of flavor in hybrid populations of P. ussuriensis is quantitative with poor flavor showing some dominance (Lantz 1929).
- 26. Conclusion - In India, very little breeding work had been done in the past in pear. Only some work was done for varietal improvement. But the region of temperate Himalayan Mountains has wide diversity of Pyrus and Cydonia. So, it is very important to exploit them which may be suitable breeding materials in future. Rootstock breeding to combine specific traits like higher yield, improved fruit quality, resistance to different biotic and abiotic factors along with graft compatibility, is going on in different pear breeding station around the world.
- 27. Reference – • M.R.Dinesh,(2015).Fruit breeding • A.S.Salaria,(2015).A2 Z Solution horticulture at a glance • S Sahoo,D B Ramesh, P K Panda & Vibhuti N Mishra,(2002).Plant Resources Utilization. • https://www.ishs.org/ishs-article/918_128 • http://www.nbpgr.ernet.in/Downloadfile.aspx?EntryId=6013 • https://eurekamag.com/research/000/819/000819438.php • https://www.hindawi.com/journals/aag/2014/541097/ • https://fruits.edpsciences.org/articles/fruits/pdf/2009/02/i9204.pdf • https://ndpublisher.in/admin/issues/IJAEBV9N3g.pdf • https://www.actahort.org/books/671/671_33.htm • https://www.researchgate.net/publication/326527129_Pear_Pyrus_spp_Breeding_Volu me_3