Maize Genetics Cooperation Newsletter vol 84
2010
Please Note: Notes submitted to
the Maize Genetics Cooperation Newsletter may be cited only with consent of
authors.
callusogenesis,
somatic embryogenesis and plant regeneration in F1 hybrids of maize.
Climenco O.A, Kravchenko A.N., Jacota A.G.
Institute of Plant Genetics and Physiology
Chisinau, Republic of Moldova
The purpose of this study was
to determine heritability and correlation of such characters as callusogenesis, somatic embryogenesis
and plant regeneration. 20 hybrids F1 (Co125 x P502, Co125 x MK390, Co125 x MK159, Co125 x MK01,
Co125 x P101, 092 x P502, 092 x MK390, 092 x MK159, 092 x MK01, 092 x P101, A239
x P502, A239 x MK390, A239 x MK159, A239 x MK01, A239 x P101, 459 x P502, 459 x
MK390, 459 x MK159, 459 x MK01, 459 x P101) were used as experimental material.
Tissue cultures were initiated from 12-13 day-old immature embryos. The data
were processed by analysis of variance (Statgraphics Plus 5.1) and coefficients of heritability (h2) for
the characters under study were calculated. For the comparison of the
relationships between the processes of calusogenesis, somatic embryogenesis and
plant regeneration correlation coefficients were determined among parental inbred lines as well as among
hybrid combinations.
Highly
significant differences of the frequency of embryogenic callus formation and
plant regeneration process among F1 hybrids were found out. Such
combinations as A239 x P502 and A239 x MK159 proved to be the best for somatic
embryogenesis (83,58% and 86,89%, respectively). However, A239 x MK159 hybrid
had much lower frequency of plant regeneration process than that of A239 x P502
hybrid (34,96% and 76,54%, respectively).
It was also found out that hybrid combination 092 x P502 had rather high
frequency of the processes under study (somatic embryogenesis – 73,39%
and plant regeneration – 67,78%). In addition, in 4 hybrid combinations
the processes of somatic embryogenesis and plant regeneration were not
observed.
Correlation
analysis showed that for all the inbred lines (parental forms for F1
hybrids) between the somatic embryogenesis and plant regeneration processes a
positive correlation was found (r = 0,69
P<0,05). At the same time, for F1 hybrids a positive
relationship (r = 0,44 P<0,05)
between callus formation and somatic embryogenesis was determined. A similar
relationship exists between callusogenesis and plant regeneration (r = 0,48 P<0,05). However, the correlation
between somatic embryogenesis frequency and plant regeneration frequency was
much stronger ( r = 0,95
P<0,001) than that of parental lines. Among F1 hybrids a
strong negative correlation (r = -0,87
P<0,001) was observed between embryogenic callus formation and non-embryogenic callus formation.
It should be noted that the somatic embryogenesis and plant regeneration
also negatively correlated with non-embryogenic callus formation ( r =
-0,43 P<0,05 and r = -0,56 P<0,01, respectively).
Embryogenic callus formation
was positively correlated (r =
0,66 P<0,001) with plant regeneration.
Heritability
for the processes under study was estimated on the basis of two-factor analysis
of variance. Coefficients of heritability are presented in table 1. It was
shown that male parent and interaction of both parents had the highest values
of heritability for callusogenesis, somatic embryogenesis and plant
regeneration processes. Female parent had the lowest heritability value and this
coefficient was significant only for non-embryogenic callus formation process.
Table 1
Coefficients of heritability for the characters
under study.
Character |
h2 for female parent |
h2
for male parent |
h2 for interaction of both parents |
Embryogenic callus formation |
- |
0,47*** |
0,32* |
Non-embryogenic callus
formation |
0,26*** |
0,35*** |
0,31*** |
Plant regeneration |
- |
0,47*** |
0,41*** |
* - P<0,05 ** - P<0,01
*** - P<0,001
Taking into account relatively high heritability
values of male parent,
heritability coefficients of
male parent for each hybrid combination were calculated on the basis of
single-factor analysis of variance (table 2). It should be noted that the
highest values of male parent heritability were registrated in case when inbred
line A239 was used as a female parent.
Table 2
Heritability corfficients (h2) of male parent in F1
hybrids.
female
parent |
male parent |
characters |
||
Embryogenic callus formation |
Non-embryogenic callus formation |
Plant regeneration |
||
Co 125 |
p502 |
0,692* |
0,665* |
0,731* |
MK390 |
||||
MK159 |
||||
MK01 |
||||
P101 |
||||
092 |
p502 |
0,396* |
0,366* |
0,438* |
MK390 |
||||
MK159 |
||||
MK01 |
||||
P101 |
||||
A239 |
p502 |
0,773** |
0,823** |
0,919** |
MK390 |
||||
MK159 |
||||
MK01 |
||||
P101 |
||||
459 |
p502 |
0,293* |
0,538* |
0,888* |
MK390 |
||||
MK159 |
||||
MK01 |
||||
P101 |
* - P<0,05 ** - P<0,01
In
contrast, the lowest coefficients of heritability for the processes under study
were observed when inbred line 092 was used as a female parent. The lowest
value of male parent heritability for embryogenic callus formation was noted
when 459 inbred line was used as a
female parent.
Thus, these results can be used in the elaboration
of new and improved methods of obtaining maize regenerants.