Citrus breeding methods were presented by S. Sharvesh. Key points include: - Citrus includes oranges, mandarins, lemons, limes, and grapefruits which are important fruits in India. - Breeding methods aim to develop new varieties with traits like improved yield, quality, disease resistance. - Techniques discussed were classification of citrus species and varieties, their botany, flowering behavior, hybridization and selection of superior types. - Important commercial varieties in India are Nagpur mandarin, Washington navel orange, acid lime, Rangpur lime, Eureka and Lisbon lemons.

2. CITRUS BREEDING METHODS
PRESENDED BY
S. SHARVESH
M.Sc. HORTICULTURE,
DEPARTMENT OF HORTICULTURE,
FACULTY OF AGRICULTUR,
ANNAMALAI UNIVERSITY.

3. CITRUS
 These fruits are rich in vitamin-C and are known for their sweet
acidic taste and refereshing qualities.
 In India, this group of fruits comes third position next to mango
and banana.
 Most of citrus spp is a native of South East Asia and Indo China.
Citrus
Scientific Name Citrus spp
Family Rutaceae
Chromosome Number 2n=18

4. Botany
o Citrus spp are much branched
evergreen trees, growing upto 4-8 m
o These aromatic trees bear alternative
unifoliately compound leaves with
numerous gland dots.
o The leaves are some what leathery in
texture.
o Spines arises from the axis of leaves.
o Petioles are in general winged, except
in lemon and citron.
o The fruits are hespiridium with five
locules.

5. Fruit : Hesperidium

7. Inflorescence
• Inflorescense in citrus species is of cymose type.
• Flowers are staminate and hermaphrodite borne singly or in small
groups in the leaf axils on the young twigs.
• Flowers are produced on current season growth in cymes, both axillary
and terminal position.
• The flowers are white in colour in most of the species except lemon and
citron where they are purplish on the outside.
• Flowers have a five petals alternating with sepals, the calyx is cup-like
with five sepals and corolla.
• Stamen-numerous (15 to 30 numbers)

9. • The viability of pollen varies from 45-80%
depending upon the season.
• Generally anthesis takes place in morning
hours between 9am-12 noon.
• Dehiscence of anthers takes place at different
time viz, in lemon before anthesis, in sweet
lime after anthesis.
• In most of citrus sps stigma receptivity starts
2-3 days earlier to anthesis and last for four
days after anthesis with maximum receptivity
on the day of anthesis.
• Temperature also affects the activity of bees,
the main citrus pollinator.

10. Flowering
• Citrus species show a relatively long juvenility period
before the trees reach the mature stage to produce flowers.
• They usually produce a large number of flowers over the
year.
• The floral load depends on the cultivar, tree age and
environmental conditions (Monselise, 1986).
• The flower bud induction initiated in November and may
continue upto early January.
• Full bloom stage appears in spring.
• In tropical climates, however, bud sprouting and flowering
come about without interruption throughout the year
although the main bloom still occurs during the spring
(Goldschmidt, 1996).
• In subtropical regions, citrus major bloom occurs during
the spring flush along with the vegetative sprouting.

11. Three flowering seasons in citrus

16. Classification
Genera
Poncirus Fortunella Citrus

17. Poncirus
• Poncirus trifoliate – central and northern china
• Rootstock –resistant to phytopthera and nematodes
• Small evergreen shrub or tree
• Trifoliate leaves
• Polyembroyonic

18. • Kumquats
• Native to south east china
• Small evergreen shrub
• Spines with dense branches
• Unifoliate
Types
• F. margarita
• F. japonica
• F. hindsii
• F. crassiflora
F. margarita
F. crassiflora

19. Citrus Classification
• Swingle : 16 spp
• Tanaka: 144 spp
• Bhattacharya and Datta(1956): 78 spp in
India.
• Hogson reported 159 spp and classified
citrae into Citrus, Poncirus and
Fortunella.

20. Classification by Tanaka
Genus Citrus (2 subgenus, 144 species)
Subgenus –Archicitrus
(5 section, 98 species)
Subgenus –Metacitrus
(3 section, 46 species)
Section Papeda (12 species) Section Osmocitrus (9 species)
Limonellus (16 species) Acrumen (36 species)
Citrophorum (21 species) Pseudofortunella (1 species)
Aruntium (28 species)
Cephalocitrus (21 species)

21. Classification by Swingle
Genus –Citrus: (2 sub genera, 16 species, 8 botanical varieties)
Sub genus Eucitrus (10 species) Sub genus Papeda (6 species)
C. medica (citron) C. ichangensis
C .limon (Lemon) C.latipes
C .aurantifolia (Lime) C.micrantha
C.aurantium (Sour lime) C.celebia
C.sinensis (Sweet lime) C.macraptera
C. reticulta (Mandarin) C.hystrix
C.grandisi (Pummelo)
C.paradisi (Grape fruit)
C.indica (Indian wild orange)
C.tachibana (tachibana orange)

22. 1). Acid group 2) Oranges
C. limon - Lemon C. aurantium –Sour orange
C. aurantifolia- Sour lime C. sinensis – Sweet orange
C. jambhiri – Rough lemon 3) Mandarins
C.limettoides- Sweet lime C. reticulata
C.limetta C. unshui
C. medica- citron C. nobilis
4) Pummelo group. 5) others
C.paradisi C.limonia
C. grandis C.bargania
C. myrstifolia
Hodgson , Horticultural classification -5 categories

23. Varietal wealth of citrus

25. Sweet orange (Citrus sinensis)
• Evergreen
• Flowers borne solitary
• Tight skinned oranges
• Round to oval
• 10-12 segments.
• Highly polyembryonic
4 groups
• Spanish group – sathgudi, mosambi, hamlin and shamouti
• Blood orange group – malta and blood red
• Mediterranean orange – jaffa, pineapple and valencia late
• Navel orange – washington navel orange

26. Chance seeding from Florida. Early variety, smooth ,medium and apex
Varieties :-
•Hamlin:-
round.
•Jaffa:- Mid season variety. Suitable for arid region.
•Pineapple:- Mid season variety.
•Valencia:- late season variety. Fruit medium to large , round or slightly oval type .
•Mosambi:-
•Satgudi:-
Most popular in Maharastra , Best rootstock- Rangpur lime.
Most popular in Andhra Pradesh, granulation suseptible variety
•Blood Red :- Most popular in North India Best rootstock – karna khatta
•Shamouti :- Seedless variety, fruit medium to large and sweet rich in flavor.
•Washington navel:- Variety is originated in Brazil and introduced to Washington during
1870.

28. Washington Navel
Sathgudi

30. Sweet orange Hybrids
 Ambersweet- Clementine x Orlando tangelo, Dual purposes
 Chironja- Sweet orange X Grapefruit, Mid season variety, fruit holds well
on tree.
Ambersweet Chironja

31. Sour orange ( Citrus aurantium)
• Used as rootstock –
sweet orange and
mandarin
• Semi dwarf
• Resistance to soil borne
pathogens
• Tolerant to cold stress
• Susesptible to tristiza

32. Mandarin : Citrus reticulata
• Loose-skinned oranges are commonly designated as
mandarins.
• Flowers white.
• Fruits depressed-globs, 5-8 cm in diameter, 10-14
segments, contain tangerine as prominent glycoside.
• Pulp sweet and juicy, orange in colour, seeds highly
polyembryonic.
Varieties:-
1.Coorg:- Most important commercial variety in South India.
2.Khasi;- Locally known as Sikkim or kamala mandarin.
3.Nagpur (Ponkan):-Finest mandarin in the world. Grown in Satpuda hill in
Maharashtra.
4.Emperor and Fuetrelles:- Introduction from Australia.
5.Sutwal:- Introduction from Nepal.
6.Satsuma(seedless) - Commercial variety of Japan

33. Nagpur mandarin
• Finest variety in the world
• It has unique acid-sugar blend that is not
found in any other orange across the world.
• Light reddish, bright yellow to full orange
colour
Kinnow mandarin
• Cultivated in Punjab
• The fruit is medium-size somewhat oblate in
shape, rind moderately thick adherence with
the pulp
• Glossy fruit colour ,yellowish orange at full
maturity, segments 9 to 10, firm pulp

34. Coorg mandarin
• It is commercial variety of South India.
• Fruits are oblate to globose, golden
yellow coloured, with depressed base
and abundant juice content.
Khasi mandarin:
• The cultivar is commercially grown in
North-eastern region of India.
• It is polyembryonic in nature and
keeping quality is good.

36. Calamondin-Small Mandarin

37. Species of mandarin
• C. reticulata
• C. unshiu (Satsuma) - seedless
• C. deliciosa (Willow leaf)
• C. reshni (spice mandarin)
• C. nobilis (King)
• C. temple(Temple).
• Kinnow mandarin (king x willow leaf)
• Cleopatra mandarin (Citrus lycopersicaeformis)
• C. tangerine (Tangerine orange var Dancy and clementine)

40. SWEET ORANGE MANDARINS
Citrus sinensis Citrus reticulata
Tight skinned Loose skinned
No central hallow core Central hallow core present
Oranges are more round in shape, Mandarins are flatter at ends.
Varieties : Mosambi, sathgudi,
blood red malta, Washington,
navel orange etc..
Nagpur santra, Coorg mandarin,
kinnow mandarin, khasi orange
etc…

41. Lime
The lime are represented by Acid lime, Sweet lime, Tahiti lime and Rangpur
lime
Acid lime – C. aurantifolia
• Highly polyembryonic

43. PDKV Lime

44. PKM-1
Evolved from acid clones
at Periyakulum
Trees bear heavily

46. Sai Sharabati-
Clonal selection (Marathwada Agriculture University,
Parabhani)

47. ACID LIME HYBRID
Rasraj- IIHR, Banglore, Hybrid between Kagzi lime X Nepali round lemon,
Good quality fruits with moderately resistant to Canker

48. Sweet lime – C. limettoides
• Fruits are medium to large, base is
slightly necked and sweet in taste
• Mitha chikna, Persian Mitha,
mithotra
Tahiti lime – C. latifolia
• The trees are larger, more
spreading and cold-resistant,
nearly thorn less, seedless and
triploid origin, monoembryonic.
Sweet lime
.

49. Rangpur lime
• Fruit small to medium in size,
variable in form but mainly
depressed globose to round or
broadly ovate.
• Rind color yellowish to reddish-
orange, thin, and moderately
loose, with surface minutely
pitted and smooth to slightly
rough.
• Polyembryonic,
• Fruit holds on tree for a long
period.

51. Lemon :-(C. limon Burm)
• The lemon is rounded and elongate and thick skin. The pulp is pale yellow,
juicy and with an acid flavour. The skin is yellow and specially bright when it is
ripen.
Varieties are classed on the basis of fruit and tree characters into 3 groups:
(i) Eureka group
(ii) Lisbon group
(iii) Sweet lemon – Pani jamir

52. Eureka lemon :-
•The trees of Eureka lemon are medium size,
spreading almost and thorn less.
•The Eureka is a heavy yielder and begins early in
age.
•The fruits normally mature from August onwards
in thePunjab.
Lisbon lemon:
• Large and vigorous trees, spreading, shoot
upright, numerous, medium thorny.
• Fruit colour lemon yellow, surface
smooth, and shape ellipsoid to oblong,
size medium.

53. Other varieties
• Villafranca: Fruits oval-oblong, apex pointed, bear more
seeds.
• Lucknow seedless: Fruit oblong, apex tipped. seeds few or
absent.
• Nepali round: tip is as a scar.
• Kazgikalan: fruit spherical, apex slightly tipped.
• Pant lemon 1: Selection of Kagzi kalan tolerant to canker
tristiza and die-back-selfcompatible.
• Malta- Best yield and quality, Suitable for Squash making
• Meyer- Suitable for Squash making
• Seville lemon – superior fruit yield
• Nepali Oblong (Assam Lemon) - Seedless
• Aurangabad Seedless
• Baramasi and Punjab Galgal

55. Hill lemon (Citrus
pseudolemon)
Seedless Lemon –A Promising
Seedless Lemon Variety of India.

56. Rough lemon (Citrus jambhiri)

57. Hybrids
• Bush lemon – lemon x citron (Natural hybrid)
• Citrus limetta – lime x lemon

58. Citron (Citrus medica)
• The citron fruit is usually ovate or
oblong, narrowing towards
the stylar end.
• The rind is leathery, furrowed, and
adherent. The inner portion is thick,
white and hard.
• The pulp is usually acidic.
• Monoembryonic

59. LIME LEMON
Narrow to prominent petiolar wing No well developed petiolar wing
White flower Purplish tinge on outside the flower
Apex of fruit abruptly rounded, slightly
tipped
Fruit tip is usually prominent
Fruits small to medium, round to oval
shape
Fruits medium, oval to elongate shape
Skin yellow green, thin papery and shining Greenish yellow with thick rough skin
Varieties : Pramalini, Vikram, Sai-
Sharbati, Kagzi Lime, Chakradhar, PKM-
1, Seedless Lime. Etc..
Eurekha, Lisbon, etc..

60. ( / )
 The fruits are as large in size
 They have a pleasant flavour which is either sour nor bitter.
 They are subglobose to pyriform in shape.
 The rind is thick and spongy.
 The flesh may be white or pink or red depending upon the variety.
 Large leaf, broad winged petiole
 Monoembryonic

61. Varieties
 Chakkota (Devanahalli pomello)- GI Variety, Grows well on moderate
humidity
 NRCC Pummelo- 1- OPS selection, seedless, juice purpose
 NRCC Pummelo- 2- selected from landraces of NEH Region
 NRCC Pummelo- 3- Seedling selection, Good for table purpose
 NRCC Pummelo- 5- Seedling selection, Table purpose
 Hirado Buntan- Chance seedling found in Nagasaki, Cold-tolerant
 Cuban Shaddock- sensitive to cold
 Honey- Seedless and sweet
 Mato Buntan- Popular in Japan, Early in maturity
 Pomelit

62. Devanahalli Pummelo
• Citrus maxima
• Devanahalli taluk, Bangalore Rural District
• Locally known as chakkota
• Geographical Indications of Goods (Registration & Protection)
Act (GI Act) 1999 of the Government of India
• GI Application number 131 under Class 31 as a horticulture
item

64. HYBRIDS
 NRCC Pummelo- 4- Natural hybrid Red fleshed X White fleshed,
Excellent eating quality
 Chandler- Siamese Sweet (white, acidless) X Siamese Pink (acid), Early in
season, Good keeping quality
 Cocktail- Siamese Sweet pomelo X Frua mandarin, Thinner peeled

65. Grapefruit (Citrus paradisi)
• Origin- bud mutant of pummelo
• “Forbidden fruit”, “Breakfast fruit”
 It is looks like a pummelo fruit, but
has yellowish fruit rind and flesh.
 It has a juice with slight bitter taste.

66. Marsh Seedless
 This variety is known for its almost
absence of seeds, and usually
rudimentary.
 The colour is pale yellow at maturity.
Fruits ripen in December- January.
Duncan
 Fruits are large, Flesh is tender, acidic
and the sweetness is medium, very juicy.
Fruit ripen in Decmber- January.

67. Red Blush:
 This variety is liked for the attractive appearance
provided by the pigmentation of the rind and its
deep flesh colouration.
 It contain seeds (0-8), mostly aborted. Peel is
smooth, glossy, deep yellow in colour. Ripen
during lat week of November.
Foster
• Fruit are medium to large, oblate to spherical,
having large number of seeds with 40-50 seeds
per fruit.
• Primary colour is pale to light yellow, but
sometimes rind blushed with pink, extending
into the albedo. Fruit ripens in November-
December.

68. Flame
• Seedling sport of Ruby Red
• More cold-tolerant than Star Ruby
• Mid to late-season-February to June
Star Ruby
• 75 % of Texas grapefruit acreage
• Susceptibility to Phytophthora root rot
• Red-blushed peel

69. Oroblanco
• Triploid cultivar
• Cold hardy
• Seedless
• Early season
• California-largely cultivated
Dr. Joe Furr, USDCS, Indio, Ca, 1968.

70. Other varieties
• Walter : white fleshed, seedy
• White Marsh: White fleshed, seedless
• Thompson: Pink seedless – 1st seedless pigmented
selection from bud mutation of marsh seedless
• Hudson: Red fleshed, seedless
• Ray Ruby: deep red fleshed, seedless
• Rio Red: Deep red fleshed, seedless
• Sharanpur special - 10-15 segments, 50-100 seeds

71. varieties

72. Differences between grapefruit and pummelo
Grapefruit (C. paradisi) Pummelo (C. maxima)
Tree size large Tree size medium
Twigs glabrous Pubescent
Leaves: smaller and narrow winged Very large and broadly winged
Fruit size medium to large Large to very large
Rind thin to medium thick Thick to very thick
Pulp tender and melting more juice Pulp tough and solid, less juice
Seeds polyembryonic Seeds monoembryonic
Fruit borne in clusters Borne singly

73. Wild Citrus Species collected from Meghalaya
Wild species

75. Citrus indica- Indian wild orange
Citrus ichengensis
C.tachibana (tachibana orange)

76. Wild sweet orange species

77. Breeding methods

78. Centres of diversity
 There are three major centers of diversity in India.
 The first in the North-East including Assam and adjoining areas.
 The second diversity in south India, indigenous types include Gajanima, kichili and
some wild mandarin types.
 The third in North-West region at the foot of Himalayas where the hill lemon
(galgal) is common.
 Many of the progenitors of citrus fruits are believed to have originated in India.
These include C. latipes, C. limonia, C.pennevesiculata, C.maderaspatana, many of
these are wild types.
 Eastern India might be the centre of orgin for many citrus fruits, (Tanaka, 1981).

79. Objectives of breeding
 Producing early maturing citrus fruits with high yield and fruit
quality.
 Developing rootstocks having disease and nematodes
resistance, wider adaptability, etc.
 In rootstock breeding, the main emphasis has been given on
the development of root stock resistant to tristeza virus,
Phytophthora, nematodes, etc.

80. Problems in citrus breeding
Time
Polyembyony
Sterility
Self incompatibility
Long juvenility

81. Methods of breeding
Introduction,
Selection,
Hybridization,
Tissue culture,
 Mutation breeding,
Polyploidy breeding,
Biotechnology.

83. Phule Mosambi
•Clonal selection from Nucellar Mosambi
•High juice content (47.37%) with lower
acidity (0.40 %) and high TSS (9.66oB)
•Recommended for Maharashtra

90. Intergeneric hybrid
• Citrange – T. orange x Sweet orange
• Citrangequat - T. orange x citrange x fortunella
• Citrangor – citrange x C. sinensis
• Citrandrin - T. orange x C. reticulata
• Citromelo – P. trifoliate x C. paradisi
• Citremon - P. trifoliate x C. aurantium
• Citrumquat - Poncirus spp x F. japonica
Intrageneric hybrid
• Tangor - C. reticulata x C. sinensis
• Tangelo - C. reticulata x C. paradisi
• Limonim – C. limon x C. aurantifolia
• Limonage – C. limon x C. reticulata

91. Mutation Breeding

93.  The Hongkong wild kumquat, Fortunella hindsii been the first
reported tetraploid. Polyploid breeding seems to offer prospects to
obtain large sized fruit with dwarf plant types.
Production of triploids by crossing tetraploid with diploids may
be useful in obtaining seedless varieties.
The seedless lime (C. latifolia) a triploid. Triploids have
favorable characteristics and yield well but they are sterile.
Polyploidy manipulation by crossing of tetraploids with diploids
yielded some valuable triploid varieties like ‘Oroblanco’ and
‘Melogold’.
Polyploidy breeding
26

94. Biotechnology
• Tissue culture has been effectively used in obtaining hybrid
poncirus plantlet from polyembryonic citrus cultivars
• Poncirus trifoliate not only carries a genetic marker but also
posseses resistance to trizteza, phytopthera and cold stress,
• So intergeneric hybridization with aid of tissue culture offers
incorporation of multiple desirable parts found in different
genera for improvement of citrus rootstock and scion cultivars

97. INTRODUCTION
Characteristics
It is white fleshed and fruit weights about 700-800 gm. It has sweet taste
like Mosambi. The fruit has 15 segments which are very juicy. The
productivity is about 45-50 tonns/ Ha. Fruit mature in August and can be
harvested up to October. This is an early fruit of citrus group since
Nagpur mandarin comes to market in October.
Cutter
V
alencia
USA This is a tight jacket orange of sweet orange group and is considered best
fruit world over for processing. Fruit matures in last week of November
and can be harvested up to January. It can be used for table and juice
purpose. The yield is 21 tonnes at 6×6 m spacing and can increase up to
30 tonne at 5×5 m
Recent achievements
Recently, in 2016 ICAR-CCRI, Nagpur released citrus varieties
Pummelo USA
US -145
Varieties Country

98. Pummelo US -145
Cutter V
alencia

99. Contd...
Cultivar State Characteristics
NRCC
Pummelo – 5
Jungles of North-East
on Mizoram-Tripura
border
Fruit has excellent sweet taste and has a little tinge of
guava flavor. It is red fleshed and juicy, fruit weight is
about 800g.
The yield is high and a grown-up plant bears over 400
fruits. The yield could be 32 tonnes per hectare at 55 m
spacing.
NRCC
Grapefruit – 6
North-east region This variety also yields around 400 fruits per plant,
which is about 152 kg per plant, or 42 tonnes per
hectare.
Two varieties developed through indigenous material

100. NRCC Pummelo – 5
NRCC Grapefruit – 6

102. NRCC Mandarin seedless-4 (N4)
• No. of fruits/plant = 679
• Fruit yield per plant = 98kg
• No. of seeds/ fruit =2.58
• Acidity = 0.70 %
• TSS = 10.8
• Juice =47%