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STUDIES ON COMBINING ABILITY AND HETEROSIS IN A DIALLEL SET OF CROSSES INVOLVING DWARF GENOTYPES IN MAIZE (Zea mays L.)

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Title STUDIES ON COMBINING ABILITY AND HETEROSIS IN A DIALLEL SET OF CROSSES INVOLVING DWARF GENOTYPES IN MAIZE (Zea mays L.)
 
Creator ANNAPURNA, DHAVALA
 
Contributor HABIBUDDIN AHMED, KHAN
 
Subject STUDIES, COMBINING, ABILITY, HETEROSIS, DIALLEL, CROSSES, DWARF, GENOTYPES ,
 
Description The introduction of dwarfing genes into
normal corn has not consistently given satisfactory
hybrids. But, in view of the reports of variable
effect of br2 gene in different genetic back grounds
(Anderson and Chow, 1963; Campbell, 1965; Scott and
Campbell, 1969), the present study was conducted on
dwarf lines having "br2 ", "D" and other genes with an
aim to evolve lodging resistant maize hybrids which can
yield on par or superior to the present tall hybrids.
Ten dwarf inbred lines of maize viz., RD 9, RD
10, RD 11, RD 16, RD 18, RD 25, RD 26, RD 28, AR 238
and AR 272 with their 45 single crosses and seven tall
selected inbred lines viz., B 57, CM 202, CM 205, MO
17, Swan 1, P 108 and P 114 with their .21 single
crosses were evaluated in two yield trials in
randomized block design with three replications.
Among the dwarf hybrids, the parents P9-AR 238
with "br 11 gene and PlO-AR 272 with "D" gene produced
intermedi&te to tall "modified" dwarf types due to the
complementation of genes at different loci. Though the mean yield of tall and dwarf
hybrids was less than the check DHM 103, two dwarf F1 s
P3xP9 (RD llxAR 238) and P4xP9 (RD 16xAR 238) recorded
yields significantly higher than DHM 103. Similarly
the tall hybrid Pl4xP17 (MO 17 x P 114) yielded higher
than the check. However, lodging was decidedly less in
dwarfs than the talls as well as check. In addition,
the dwarf hybrids were early in maturity period.
Among the dwarf lines P9-AR 238 and PlO-AR 272
(The lines introduced from USA) were observed to be
good combiners for yield and its related characters.
The cross P3xP9 (RD 11 x AR 238) showed high sea effect
of yield in F1s. Whereas in talls Pl2-CM 202· recorded
sig~ificant positive gca effects for yield and its
related characters. The tallxtall hybrid Pl4xP17 (MO
17xP114) recorded high sea effect for yield.
Among the predicted dwarf double crosses, the
cross [(RD llxRD 16) (AR 238xAR 272)] is predicted to
yield 34.69% more than DHM 103. The same cross showed
less lodging of 5.73% which was less than DHM 103 by
90.03%. On the other hand the tall double cross
[(CM 202 x MO 17) (Swan lxP 114)] is predicted to yield
9. 79% mor·e · than DHM 103 with a lodging of · 57. 50 per
cent.
Correlation studies revealed that grain yield
was positively and significantly related with plant
height, ear length, ear girth, number of seeds per row,
number of rows of seed per ear, number of seeds per ear
and 1000-seed weight in both the trials. In dwarf
hybrids apart from the above characters single plant
yield was positively and significantly correlated with
ear height and number of ears per plant. However, the
flowering was observed to be negatively correlated with
yield. Path coefficient studies showed that number of
seeds per ear and 1000-seed weight had higher direct
effects in both the trials and their indirect effects
were also high. In dwarf hybrids number of ears per
plant also showed high direct effect.
Th~ above results indicate that high yielding
dwarf hybrids can be developed which can be viable and
acceptable for commercial cultivation for which further
research is suggested.
 
Date 2016-08-08T15:35:55Z
2016-08-08T15:35:55Z
1989
 
Type Thesis
 
Identifier http://krishikosh.egranth.ac.in/handle/1/71609
 
Language en
 
Relation D3189;
 
Format application/pdf
 
Publisher ACHARYA N.G. RANGA AGRICULTURAL UNIVERSITY, RAJENDRANAGAR, HYDERABAD