HERITABILITIES AND RELATIONSHIPS AMONG GRAIN-FILLING PERIOD, SEED WEIGHT AND QUALITY IN FORTY ITALIAN VARIETIES OF CORN (ZEA MAYS L.)

1980 ◽  
Vol 60 (4) ◽  
pp. 1101-1107 ◽  
Author(s):  
M. PERENZIN ◽  
F. FERRARI ◽  
M. MOTTO
Keyword(s):  
Zea Mays ◽  
Seed Weight ◽  
Zea Mays L ◽  
Grain Filling ◽  
Kernel Weight ◽  
Genotypic Differences ◽  
Dry Matter Accumulation ◽  
Grain Moisture ◽  
Wide Range ◽  
Grain Filling Period

Forty Italian open-pollinated varieties of corn (Zea mays L.), selected to represent a wide range of plant maturity and grain weight, were evaluated in 1977 and 1978 to determine genetic variances and heritabilities for length and rate of grain-filling period, kernel weight and three seed-quality traits and to examine relationships among these traits. The results showed highly significant genotypic differences and high heritability estimates for most of the traits studied. Moreover, kernel weight and rate of grain filling were found to be closely associated, although this relationship could not be statistically tested. A relatively high correlation was also detected between kernel weight and length of the grain-filling period. The increase in seed weight obtained through a delay in black-layer formation was associated with a higher grain moisture content and a decreased grain protein percentage. A further noteworthy finding of this study was the identification of two varieties which attained a large seed weight in a relatively short time through a very high rate of dry matter accumulation. The implications of these findings are discussed from a physiological and breeding point of view.

Cross-pollination effects on maize (Zea mays L.) hybrid yields

1992 ◽  
Vol 72 (1) ◽  
pp. 27-33 ◽  
Author(s):  
R. T. Weiland
Keyword(s):  
Zea Mays ◽  
Zea Mays L ◽  
Grain Filling ◽  
Maize Yield ◽  
Kernel Weight ◽  
First Year ◽  
Kernel Number ◽  
Cross Pollination ◽  
Grain Filling Period ◽  
N Fertility

Recent studies have shown that pollen from a long-season maize (Zea mays L.) hybrid increased yield of a short-season hybrid by lengthening the effective grain-filling period, while the reciprocal cross did not alter this period or yield. This effect (metaxenia) was evaluated further in the studies reported here with hybrids of more diverse maturity and under both high and low N fertility. In the first year of this study (1989), sib- and cross-pollinations were made among B73Ht × Mo17 (B × 7) and two early-silking hybrids, LH59 × LH146 (L × 6) and Pioneer 3732 (3732) under N-sufficient (275 kg ha−1) and two lower N regimes (17 and 67 kg ha−1). Only a few significant effects were observed and these were noted at high N with one exception. With 3732 pollen, grain yield of B × 7 was decreased at 275 kg N ha−1, and physiological maturity occurred 3 d earlier. Yield of 3732 was increased by L × 6 pollen in comparison with B × 7 pollen. Kernel number and average kernel weight were not altered by pollen source. Pollen type did not affect yields under low N fertility, except for a reduction when B × 7 was pollinated by L × 6 at the 67-kg N ha−1 rate. In 1990, under N-sufficient fertility, B73Ht × LH156 (B × 6), a late-silking hybrid, and LH146 × LH82 (L × 2), an earlier hybrid, were sib- and cross-pollinated with B × 7 and 3732. The only significant effect observed was that L × 2 pollen increased B × 6 yield. Thus with the hybrids used, yields of early-season types were not altered by cross-pollination with long-season types. Previous results showing increased yields when 3732 was pollinated by B × 7 were not duplicated in either year, suggesting metaxenia effects are highly dependent upon environment.Key words: Metaxenia, xenia, cross-pollination, maize, yield, N levels

scholarly journals Evaluation of inbred lines of maize (Zea mays L.) through line × tester method

2015 ◽  
Vol 39 (4) ◽  
pp. 675-683
Author(s):  
MN Amin ◽  
M Amiruzzaman ◽  
A Ahmed ◽  
MR Ali
Keyword(s):  
Zea Mays ◽  
Grain Yield ◽  
Combining Ability ◽  
Zea Mays L ◽  
Gene Action ◽  
Inbred Lines ◽  
General Combining Ability ◽  
Genotypic Differences ◽  
Mean Values ◽  
Wide Range

Maize inbred lines were evaluated by using line × tester method involving 11 lines and 3 testers for grain yield and its components through estimation of general combining ability (gca) and specific combining ability (sca) effects. Highly significant genotypic differences were observed indicated wide range of variability present among the genotypes. The crosses with high sca effect for grain yield were evolved from high × low general combiner parents which reveled additive × dominance type of gene action. The cross combinations 9MS4-1 × L22, 9MS4-1 × L486, 9MS4-2 × L431, 9MS4-11 × L486 and 9MS4- 15 × L431 with high positive sca effect having high mean values might be used for obtaining high yielding hybrids. The information on the nature of gene action with respective variety and characters might be used depending on the breeding objectives. DOI: http://dx.doi.org/10.3329/bjar.v39i4.22547 Bangladesh J. Agril. Res. 39(4): 675-683, December 2014

Effect of irrigation levels and agro-chemicals on growth parametersof summer maize (Zea mays L.

2016 ◽  
Vol 36 (3) ◽  
Author(s):  
V. K. Meena ◽  
B. P. Meena ◽  
G. S. Chouhan ◽  
B. L. Meena
Keyword(s):  
Zea Mays ◽  
Field Experiment ◽  
Plant Height ◽  
Dry Matter ◽  
Zea Mays L ◽  
Grain Filling ◽  
Dry Matter Accumulation ◽  
Summer Maize ◽  
Grain Formation ◽  
Irrigation Levels

A field experiment was carried out during summer seasons of two consecutive years 2010 and 2011 to assess the effect of irrigation levels and agrochemicals. Application of eight irrigations (at seedling, six leaf, knee-high, before tasseling, 50% tasseling, 50% silking, grain formation and grain filling stages) significantly improved plant height at harvest over rest of irrigation treatments during both the years. On pooled mean basis, the magnitude of increase in plant height at harvest due to eight irrigations was in the order of 28.41, 18.49, 10.96 and 4.31 per cent over four, five, six and seven irrigations, respectively. Dry matter accumulation at 50 Day after sowing and at harvest significantly improved with eight and seven irrigations over four, five and six irrigations during both the years of the study.

EFFECT OF TEMPERATURE DURING GRAIN FILLING ON WHOLE PLANT AND GRAIN YIELD IN MAIZE (Zea mays L.)

1983 ◽  
Vol 63 (2) ◽  
pp. 357-363 ◽  
Author(s):  
B. BADU-APRAKU ◽  
R. B. HUNTER ◽  
M. TOLLENAAR
Keyword(s):  
Zea Mays ◽  
Grain Yield ◽  
Leaf Senescence ◽  
Zea Mays L ◽  
Growth Yield ◽  
Grain Filling ◽  
Kernel Weight ◽  
Effect Of Temperature ◽  
Plant Parts ◽  
Whole Plant

In a 2-yr study, plants of an adapted, short-season single cross maize (Zea mays L.) hybrid were grown outdoors until 18 days post-silking. At that stage, the plants were transferred to controlled-environment growth cabinets where temperature effects on leaf senescence, grain and whole plant dry matter (DM) production and DM distribution were studied. The day/night temperature regimes were 25/15 °C, 25/25 °C, 35/15 °C and 35/25 °C. Higher temperatures reduced whole plant DM accumulation during grain filling. The reduction in DM accumulation was primarily related to a reduction in the period of time from 18 days post-silking until 100% leaf senescence and, to a limited extent, to a lower rate of whole plant DM production. Grain yield per plant was also lower under higher temperatures. The decreases in grain yield were almost entirely determined by a shorter duration of grain filling, while no temperature effect was observed on kernel growth rates or on kernel number per ear. During rapid grain filling, the increase in kernel DM results from utilization of a combination of assimilates temporarily stored in the vegetative plant parts and assimilates produced through current photosynthesis. Under the highest temperature regime, assimilates remobilized from other plant parts accounted for a greater proportion of kernel weight gain. In addition, there was an indication that higher night temperatures resulted in an increased proportion of gain in kernel weight resulting from remobilization of stored DM.Key words: Corn, temperature, grain-filling period, grain growth, yield components, leaf senescence

scholarly journals Combining ability estimates in maize (Zea mays L.) Through line × tester analysis

2017 ◽  
Vol 42 (3) ◽  
pp. 425-436 ◽  
Author(s):  
S Ahmed ◽  
S Begum ◽  
MA Islam ◽  
M Ratna ◽  
MR Karim
Keyword(s):  
Plant Height ◽  
Combining Ability ◽  
Zea Mays L ◽  
Gene Action ◽  
Kernel Weight ◽  
Genotypic Differences ◽  
Ability Estimates ◽  
Wide Range ◽  
Additive Gene ◽  
Ear Height

Eighteen advanced S4 lines of maize extracted from NK46 were evaluated through line × tester method by using two testers for grain yield and its components. General combining ability (GCA) and specific combining ability (SCA) effects of crosses were determined to evaluate the prospective inbred lines. Highly significant genotypic differences for all of six characters, i.e. days to 50% tasselling, Days to 50% silking, plant height, ear height, 1000 kernel weight, and yield indicated presence of wide range of variability among the genotypes for those traits. Non-additive gene action was predominant. Four lines for days to 50% tasselling, one for days to 50% silking, two for plant height, one for ear height, three for 1000 kernel weight, and four for yield were found with significant GCA effects in desired direction. For days to tasselling, days to silking, plant height and ear height, none of 36 cross combinations confirmed significant SCA effects. Five combinations showed significant positive SCA effects for 1000 kernel weight. For yield two crosses showed significant positive SCA. Considering the results of present study, based on GCA and SCA analysis of observed characters seven lines namely, NK46-2, NK46-4, NK46-10, NK46- 13, NK46-18, NK46-43 and NK46-44 were selected for further breeding programBangladesh J. Agril. Res. 42(3): 425-436, September 2017

GROWTH AND [14C] SUCROSE UPTAKE OF APICAL AND BASAL MAIZE KERNELS

1986 ◽  
Vol 66 (4) ◽  
pp. 863-869
Author(s):  
JONATHAN M. GREENBERG ◽  
TIM LLOYD SETTER
Keyword(s):  
Zea Mays ◽  
Liquid Scintillation ◽  
Zea Mays L ◽  
Dry Weight ◽  
Grain Filling ◽  
Kernel Weight ◽  
Sucrose Uptake ◽  
Sucrose Transport ◽  
The Difference ◽  
Maize Kernels

Kernels located near the apex of the ear of corn (Zea mays L.) are smaller and more likely to abort than basal kernels. Studies were conducted to evaluate the importance of time of pollination and rate of sucrose uptake in determining differences in mature kernel weight between apical and basal kernels. Simultaneous pollination of all florets in an ear did not reduce the difference in mature dry weight between apical and basal kernels or the incidences of sterility and abortion. The ability of developing apical and basal kernels to take up sucrose was evaluated by immersing the bases of detached kernels in 50 mM 14C-sucrose and measuring the incorporated radioactivity by liquid scintillation counting. Sucrose uptake increased during development, especially at the beginning of the linear phase of grain filling. Differences in sucrose uptake rate were insufficient to explain the differences between apical and basal kernels in dry weight.Key words: Carbohydrate, partitioning, corn, sucrose transport, seed development, Zea mays L.

scholarly journals Grain filling of R-nj color-selected maize strains divergently selected for kernel weight

1994 ◽  
Vol 74 (3) ◽  
pp. 455-460
Author(s):  
H. Z. Cross ◽  
M. R. Mostafavi
Keyword(s):  
Field Experiments ◽  
Grain Filling ◽  
Kernel Weight ◽  
Lag Phase ◽  
Mass Selection ◽  
Dry Matter Accumulation ◽  
Phase Duration ◽  
Color Selection ◽  
Selection For ◽  
Grain Filling Period

Grain-fill characteristics in maize (Zea mays L.) affect yield by changing kernel weight. The objective of this study was to learn how divergent tandem selection for R-nj color expression and kernel weight affected rate of dry matter accumulation (RDMA), effective grain-filling period (EFPD), and lag phase duration (LAGP). We studied development of apical, mid-ear, and basal kernels in two genetic backgrounds. We derived 12 maize strains by tandem selection within each of two early-maturing synthetics. Mass selection of synthetics NDSF and NDSD for four cycles for high (HC), random (RC), and low (LC) R-nj color expression produced six substrains. Then, four cycles of divergent mass selection for kernel weight within each color-derived substrain produced 12 substrains for study. Using the 12 strains, we conducted field experiments using a completely random experimental design within each of 2 yr at Fargo, ND. Sequential kernel samples of individual ears within each strain provided data to estimate RDMA, EFPD, LAGP, and five-kernel weight (KWT). We sampled at 3- to 4-d intervals during the linear phase of grain-filling and at maturity. Selection for HC increased RDMA but tended to decrease EFPD compared to LC strains in both NDSF and NDSD. Selecting heavier kernels increased KWT of basal and mid-ear kernels by increasing RDMA. Direct and correlated responses to R-nj color selection were evident after four subsequent cycles of divergent tandem selection for kernel weight. Therefore, R-nj expression was not a temporary maternal effect. Kernel weight selection responses differed among the color strains and synthetics. Kernel weight seemed mainly determined by RDMA that was affected by selection for R-nj color expression and for kernel mass. Key words:Zea mays L., aleurone color, mass selection, correlation, yield components

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