“Advances in 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.

12. Dormant spur
Full bloom
12

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

16. Insect pollinated

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