Muskmelon breeding

Muskmelon breeding

1. Muskmelon Breeding
Indranil Bhattacharjee
Scientist
Directorate of Research, SHUATS
Prayagraj

2. Kingdom: Plantae
Clade: Angiosperms
Clade: Eudicots
Clade: Rosids
Order: Cucurbitales
Family: Cucurbitaceae
Genus: Cucumis
Species: C. melo L.
Scientific classification
Genomic information
NCBI genome ID 10697
Ploidy diploid
Genome size 374.77 Mb
Chromosomes No. 12 (2n = 2x = 24)
Year of completion 2012
Monoecious
Sub Species
C. melo agrestis and C. melo melo
Nutrition (per 100 gram)
•34 calories
•vitamin A (68% DV)
•vitamin C (61% DV)
•90% water
•9% carbohydrates
•less than 1% protein
•less than 1% fat

3. Center of origin
•Indigenous to East Africa
•Introduced to the West Indies from Africa
•C. sativus and C. hardwickii, are natives of Asia.
•Secondary centres of diversity
•India, Persia, China and Southern Russia are considered for
muskmelon.
•In addition several wild forms occur in Africa and India and all of
these are inter-fertile.

4. Economic Importance
•Muskmelon is one of the most economically important cucurbits
•Cultivated in many tropical, subtropical and temperate regions
around the world.
•Winter production in parts of Africa (e.g. Sudan and Kenya) for
export to northern Europe has increased its importance as a cash
crop.
•It is a good cash crop in Asia and South American countries.
•It is produced as protected crop under unheated polythene tunnels
in the Mediterranean region.
•Area (India) 1.66 lakh ha
•Production (India) 10 tons of hybrid melon and 300 tons of Ops
•Total contribution to GDP (Indian) - Rs. 25 crores of seed business
•World production (2005) - 28 million tons [China (15.1 mt), Turkey,
Iran, Spain, and USA [1-1.7 million tons each].

10. Variability in traits of interest
•Plant size: 1-10 m
•Fruit weight: 10 g – 10 kg
•Fruit flesh TSS: 3 – 18%
•Fruit flesh acidity: pH 3 – 7
•Its polymorphism in leaf, flower, fruit shape, and colour, allowed
the classification of horticulturally important melons into seven
groups

12. Classification of melons
1. C. melo var. cantaloupensis Naud.: medium size fruits, round shape, smooth
surface, marked ribs, orange flesh, aromatic flavour and sweet.
2. C. melo var. reticulatus Ser.: medium size fruits, netted surface, few marked ribs,
flesh colour from green to red orange.
3. C. melo var. saccharinus Naud.: medium size fruits, round or oblong shape,
smooth surface with grey tone sometimes with green spots, very sweet flesh.
4. C. melo var. inodorus Naud.: smooth or netted surface, flesh commonly white or
green, lacking the typical musky flavour. These fruits are usually later in maturity
and longer keeping than cantaloupensis.
5. C. melo var. flexuosus Naud.: long and slender fruit eaten immature as an
alternative to cucumber.
6. C. melo var. conomon Mak.: small fruits, smooth surface, white flesh. These
melons ripen rapidly, develop high sugar content but little aroma.
7. C. melo var. dudaim Naud.: small fruits, yellow rind with red streak, white to pink
flesh.

13. Botany of Muskmelon
Classification of important species of the genus Cucumis based on
botanical features:
– C. anguria Leaves deeply lobed, fruits small, prickly lemon –
yellow when mature.
– C. sativus. Leaves shallowly lobed, fruits large, mostly oblong
– C. melo. Fruits glabrous or pubescent, smooth or netted, mostly
with sutures
•Fruits are spiny, muricate or echinate
•Polymorphic species
•Mostly andromonoecious (staminate and perfect flowers) [but
other sex forms are also available].
•Stem is soft-hairy to glabrous, striate or angled,
•Leaves are orbicular to ovate to reniform, usually five angled,
sometimes shallowly three to seven – lobed, hairy or somewhat
scrabrous, 3-5 inches across.

14. Floral Biology
•Staminate flowers are clustered.
•Pistillate flowers are solitary on short stout pedicels.
•All of them hybridize readily with each other and there is apparently
very little sterility even among progenies from crosses involving
variant types.
•Under open natural system, it is often cross pollinated by bees
•There are reports of obtaining vigorous lines by inbreeding up to 25
generations.
There are various horticultural forms within C. melo based on fruit
characteristics:
•Canta­loupes,
•Nutmeg muskmelons,
•Winter melons,
•White- skinned melons,
•Snake melons,
•Oriental pickling melons,
•Mango melons,
•Pomegranate melons

16. Pollination of Muskmelon:
•Melons may be andromonoecious (hermaphrodite and staminate
flowers), gynoecious (only pistillate flowers), or monoecious
(pistillate and staminate flowers).
•Monoecious and andromonoecious are most common.
•Hand pollination of andromonoecious types is a two-step process.
•On the day prior to anthesis, the hermaphrodite flower is
emasculated.
•Both pistillate and staminate flowers are covered to prevent insect
contamination.
•Emasculation is not required on gynoecious and monoecious types.
•Hand pollination is done at anthesis by gently rubbing pollen from
anthers of staminate parent flower on the stigma of the pistillate
parent flower.
•Pistillate flower after pollination is covered to prevent
contamination by insects like honey bees and Apis spp. etc.
•Emasculation and pollination can be done as one step procedure
also in afternoons.

20. Genetic Resources of Muskmelon:
Accession preserved in Gene banks in different countries
•Russia (2900 acc),
•USA (2300 acc),
•France (1800 acc)
•China (1200 acc),
Melon is not included in the International treaty for multilateral
access to plant genetic resources for food and agriculture and this
could reduce the exchange of accessions collected after 1993.
Collaborations between gene banks is increasing for instance with
the European Cooperative Programme for Crop Genetic Resources
Networks (ECP/GR).
Descriptors for melon have been prepared by the International
Plant Genetic Resources Institute (IPGRI).
Wild melons are underrepresented in the gene bank.
Up-to now no exclusive character has been observed only in wild
melons; for instance wild melon can be resistant to powdery mildew,
but the same trait is also found in cultivated landraces.

21. Genetic Diversity in Musk melon
•Genetic resources can be structured by geographical origin and by
phenotypic traits (botanical groups).
•Other characters e.g., Isozymes have been used as markers of the
polymorphism since the 1980.
•Polymorphism has also been studied with different types of
molecular markers (RAPD, RFLP, AFLP, SSR).
•Relationship between the botanical groups and biochemical and
molecular markers has been investigated.
•In general, accessions belonging to a botanical group fall in the same
cluster determined by the molecular markers.
•But in many cases, accessions of different geographical origin
belonging to one cultigroup are in different clusters.
•Molecular markers have not yet been used for the management of
collections, for instance in the definition of core-collections.

22. Genetic Diversity in Musk melon
In India, there is enormous variability and several landraces
adapted to local situations are available.
The pockets of rich diversity in India are Eastern UP, Lucknow,
Shahjahanpur, Bareilly, Mathura, Agra, Meerut and Rajasthan.
The germplasm lines are conserved at IIVR, Varanasi and SAUs like
PAU, GBPUAT and Rajasthan Agriculture Univ., Research Station,
Jaipur, SHUATS, Prayagraj.
There is a need to explore and conserve farmers varieties.

23. Sex Expression:
From the crosses of hermaphrodite x monoecious types F
2

segregation conforms to a typical di-genic ratio
G – A – = ++ = 9 monoecious
G – aa = + a =3 andromonoecious
ggA – = g + = 3 gynomonoecious
ggaa = ga = 1 hermaphrodite
•Environmental factors and interaction with other genes give rise to
various other sex forms in muskmelon.
•There is an association between fruit shape and sex form.
•Fruit shape of monoecious and gynoecious lines is oblong and
perfect flowers produce round fruits, however, exceptions have also
been reported.

25. Pitrat (2008) has illustrated genetic control of sex expression in
melon and effect of ethylene and silver nitrate on melon sex
modification as follows:

26. Genes in Muskmelon

36 genes as listed
by Robinson
(1976) are given
>>>>>>>>>>>>>>>

27. Breeding Objectives of Muskmelon:
1. Attractive round shape/spherical fruit shape
2. Thick flesh with attractive orange/green colour
3. Small seed cavity
4. Sweet, juicy, musky flavorsome fruits
5. TSS not less than 10%
6. Tough netted skin of fruit
7. High early and total marketable yield
8. Resistance to common diseases (powdery mildew, downy
mildew, virus, fusarium wilt, gummy stem blight)
9. Resistance to important insect-pests (aphid and leaf miner)

29. Fruit Quality / Market Traits:

(i) Rind colour
(ii) Stem scar size (for those that slip at
maturity)
(iii) Blossom scar size
(iv) Fruit size
(v) Fruit shape
(vi) Overall appearance
(vii) Percentage net cover
(viii) Net type
(ix) Surface cracks
(x) Ground spot (area contacting soil)




(xi) Rind roughness
(xii) Flesh colour
(xiii) Rind thickness
(xiv) Flesh thickness
(xv) Seed cavity
(xvi) Dryness
(xvii) Flesh firmness
(xviii) Flesh texture
(xix) Flavour
(xx) Total soluble solids

30. Breeding Methods/Selection Criteria of
Muskmelon
Controlled Inbreeding
Pedigree Method
Backcrossing
Heterosis Breeding
Mutation Breeding
Transgenic Breeding
Gene Editing

31. Sources of Disease and Insect Resistance:
According to McCreight (1993) and Dhiman (1995) the
sources of resistance to diseases and insect-pests in
muskmelon are given in Table 27.2.

36. Exploitation of Sterility in Hybrid Seed Production
The male sterile line (ms
1 ms
1) is maintained by crossing to the isogenic
maintainer heterozygous for recessive sterility allele

41. Seed Production of Muskmelon:
Isolation Distance:
1. Breeder/foundation seed – 800 m
2. Certified seed – 400 m
3. Different groups of melons within C. melo are all cross-
compatible.
4. No viable seed production if cross pollinated with
cucumber (C. sativus)

43. Harvesting:
•Fruits of cantaloupe and muskmelon types tend to separate from
the stem at the base of the fruit as the fruit becomes fully mature.
•This stage of separation by formation of an abscission layer is
known as ‘Full-Slip’. Fruits are harvested/collected at this stage.
•When there is no abscission layer formation, the fruit maturity is
indicated by external rind colour change from green to yellow or
yellow to white. The seeds are washed without fermentation.
Seed Yield:
1. 300-500 kg/ha
2. 1000 seed weight – Approximately 25 g

44. Varieties of Muskmelon
Hara Madhu:
This is a variety developed at PAU, Ludhiana from the local material
of Kutana type (a local collection of UP). It was identified in 1975 for
zones IV and VII. Vines are 3-4 m long and vigorous. Fruits are large,
round, slightly tapering towards the stalk end. There are 10
prominent green sutures. Average fruit weight is 1.0 kg. Flesh is
green, with small seed cavity. TSS is 12-13%. The yield potential is
125 q/ha.
Pusa Sharbati:
This has been developed at IARI from a cross of Kutana x PMR 6 of
USA. It was identified in 1975 by the vegetable workshop for
northern-Gangetic plains. It is suitable for riverbed conditions also.
Fruits are round with netted skin. Flesh is thick and orange. TSS
content is 11-12%. Yield potential is 150 q/ha.

45. Arka Rajhans:
It is a selection from local collection (IIHR-107) of Rajasthan at IIHR,
Bangalore. It was identified in 1975 for better fruit quality and yield
attributes. Fruits are round-slightly oval, medium large, with white, firm
flesh having 11-14% TSS. Average fruit weight is 1.25-2.0 kg. It is
moderately resistant to powdery mildew.
Arka Jeet:
It is an improvement over the commonly available local type of Lucknow
area. It was developed at IIHR, Bangalore (IIHR 103). It was identified in
1975 for zones VI and VII. Fruits are small, flat-round, with attractive
orange flesh, weighing 300-500 g. Flesh is white and sweet with medium
soft texture.

46. Punjab Hybrid:
This is an F
1
hybrid developed at PAU, Ludhiana having the parentage
as male sterile MS-1 X Hara Madhu. Identified in 1985 for zones IV
and VIII, Punjab Hybrid has 2-2.5 m long vines, vigorous luxuriant
growth, globular fruits with distinct sutures, weighing about 800 g.
Flesh is creamy yellow. Rind is netted. TSS is about 12%. It is early in
maturity, has good post-harvest life and transportability. It is
moderately resistant to powdery mildew.
Pusa Rasraj:
A monoecious line M-3 developed at IARI and crossed with
Durgapura Madhu gave rise to the F
1
hybrid, Pusa Rasraj. It has been
recommended for commercial cultivation in Delhi, UP, Punjab,
Haryana, and Bihar by Project Directorate, All India Coordinated
Vegetable Improvement Project in June, 1990.

49. •Private Sector Veg. Seed Companies are largely selling
hybrid seeds of muskmelon imported from Taiwan, China,
Japan, etc. These hybrids have better shelf-life.
•Deepti is most common Private Sector hybrid.

51. Biotechnology of Muskmelon
•Melon Regeneration (vitro cultures )
•Biochemical and Molecular Markers (GWS, MAB & MAS)
•Genetic Transformation (ABT, Vectors)
•Gene Editing (Crisper CAS9)

Integration of New Biotechnologies in Breeding Programmes
Melon has a small genome size, estimated at 450-500 Mbp (1C).
A chloroplast genome has been estimated at 150 kbp.
Mitochondrial genome is of 2400 kbp.

52. An International Cucurbit Genomics Initiative started in 2005
(genetic and physical maps, EST-expressed sequence tags, B AC-
bacterial artificial chromosome libraries and genome sequencing)
http://cuke.hort(dot)ncsu.;edu/cgc/index.html
Several types of population have been used:
1.F
2
,
2.BC,
3.doubled haploid (DH)
4.recombinant inbred lines (RILs).
•Genes and QTLs controlling phenotypic traits have been localized.
•BAC and EST libraries are available and provide new sequences
which can be used as markers.
•The next step will be the merging of these different maps in a
consensus one using anchor points such as microsatellites (SSR).
•The development of genetic maps allows the use of marker
assisted selection (MAS).
•Breeders can use markers closely linked with genes or QTLs of
horticultural interest such as disease resistance, fruit quality or
flower biology.