الفهرس 
Material and methodsOnly 14 pages are availabe for public view
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Abstract
The present stQdies on heterosis, combining
abilities, and genetic behavio~r in Muskmelon
(C~cumis melo L.) were cond~cted in the Farm of
Faculty of Agriculture at Moshtohor, Zagazig
Univ., Banha Branch, during the years 1981-1984.
The experimental material consisted of selfed
lines of five M~skmelon varieties, two loc~Jl
vars. (Shahd Edfina and Bassosi), three exotic
could be summarized as follows :_
1- Genetic differences among the genotypes were
highly significant for all the characters studied.
f
2- Heterosis values measured as departure from the
average mid~parent and better-parent were significant
for all the characters studied except for avel~ge
f~it weight per plant.
J- Both general and specific combining abilities
were highly significant for all characters studied.
The additive gene effects were more important than
non-additive gene effects for all characters except
for yield characters.
Tests for reciprocal differences were significant
for all characters studied.
5- The exotic varieties, Ezeatananas and Magyarkincs
were good general combiners for flowering time, number
of days to maturity and yield characters. The exotic
varieties, Magyarkincs and Charentais were good general
combiners for fruit characters. The local variety,
Shahd Edfina was a good combiner for yield characters
and fruit shape index. Meanwhile, the local variety,
Bas~osi was poor general combiner in comparision to
the other four varieties.
6- The best combiners were presented in the crosses
of (Shahd Edfina X Magyarkincs) for number of days to
first male flower anthesis, (Ezeatananas X Bassosi)
for days to first female or hermaphrodite flower anthesis,
(Magyarkincs X Bassosi) for number of days to
ma1lurity, (Shahd Edfina X Charentaia) for yield, shape
index and T.S.S. characters, and (Ezeatananas X Magya~
kincs) for fruit flesh thickness.
1- The addi tive genetic variance were more important
than the dominance genetic variance for all charac tera
except for number of tru1 ts per plant.
8:” The average degree ot dominance was tound to be
arti~l dominance tor all characterse%cept tor liumer
of fruits per .plant, 1fhich showed overdom1nanoe.
I ’9· The negative and pos1 tive alleles were not equa-
I
ly distributed among the parental popu.lat1ons in
11 cases,
O-The proportion ot dominant to recess1Te genes,
ruggested that the dominant genes are in excess in
~he parents. tor number of days to open the first teale
or hermaphrodite flower, number of days to matuty,
and yield characters. While the recessive gen ••
re predominant for number of days to open the first
ale nower and f:ru1 t characters.
+1- All characters were tound to be under the control t:t’ one grou.p ot genes exhib1 ting dominance.
a- High narrow sense her! tabili ty values were deteoted
or flowering time, nLlDber of days to maturity, trui t
hape index, and total soluble solids. Lowvalue ot
arrow SeDse ben. tab!11 ty was obserYed tor ntaber ot
:nti ts per plant.- While the average trui’li .eight per
lant and lru! t fiesh thickness exhibited 1ntexmediat.
arrow sense her! tab!l1 t7 Talues.
J- The ae10tic tea’tllr •• ot the tlve Tar! .tie. and
heir teD different JQ-br.ld. were stud1ed at ••• pha••
• The pairing ot the chroJao8Oll.es was coapl.tely normal with twelve bivalents. The chromosomeswere all
small, the largest one being (39.28Mm) length. The
karyotype can be classified into metacentric, submetacentric,
sub-telocentric, and telocentric. Two
pair of the chromosomesincluded satellites.
14- The number of days to first male nower anthesis
showed significant posi tive phenotypic correlations
with each of date of the first female or hennaphrodite
flower anthesis, number of days to maturity, and
with total soluble solids. It showed significant negative
correlation with fruit flesh thickness. Date of
the first female or hermaphrodite nower anthesis
showed significant positive correlation with number
of days to maturi ty. Meanwhile, it showed significant
negative phenotypic correlations with each of fruit
flesh thickness and total soluble solids. Number.of
days to maturi.ty showed significant negative phenotypic
correlations wi th each of frui t nesh thickness
and total soluble solids. Numberof fruits per plant
showed significant posi tive phenotypic correlations
wi.th each of average frui t weight per pl8.l1t and total
soluble solids. Fruit nesh thickness showed significant
pasi tive phenotypic correlation with total soluble
solids.