scholarly journals DNA METHYLATION AND FESOD GENE EXPRESSION AFFECTED BY PLANT DENSITY IN ZEA MAYS L.

2019 ◽  
Vol 50 (Special) ◽  
Author(s):  
Shenawa & Alfalahi
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Zea Mays ◽  
Zea Mays L ◽  
Plant Density ◽  
Maximum Level ◽  
Planting Density ◽  
Gene Copies ◽  
High Plant Density ◽  
Different Response

Methylation Sensitive Amplification Polymorphism (MSAP) was used to characterize the alterations in DNA methylation in maize (Zea mays L.) inbred lines and their half-daillels affected by plant densities (213333 plant h-1 and 13333 plant h-1). The two restriction was enzymes ( HpaII and MspI) succeeded in diagnosing a total of 23 specific loci, most of (22 loci) were Methylation Sensitive Loci (MSL), while the only one NML (No Methylated Loci) was monomorphic. Thirteen out of 22 MSL loci polymorphic, recording a were polymorphism percentage of 59%. Results of FeSOD gene expression cleared the different response of maize inbreds and hybrids to high plant density stress. Generally, the expression of  the targeted gene was increased in plants submitted to high plant density stress compared with low density. The inbred 3 and its single hybrid 1×3 achieved the highest level of gene expression under high planting density (5505.7 and 21098.6 copy, respectively), meanwhile, inbred 5 and it's single hybrid 4×5 gained the maximum level of FeSOD expression at the low plant density (8317.6 and 6862.1 copy, respectively). The response reached to its maximum limit in many of those genotypes, some other genotypes showed relatively steady performance along with higher stress, such as parent 1, that gave the lowest number of gene copies in both, high and low plant density (1375.8 and 1569.5 copy, respectively).

CORN YIELD RESPONSE TO IRRIGATION, PLANT POPULATION AND NITROGEN IN A COOL, HUMID CLIMATE

1986 ◽  
Vol 66 (3) ◽  
pp. 453-464 ◽  
Author(s):  
D. M. BROWN
Keyword(s):  
Zea Mays ◽  
Soil Moisture ◽  
Zea Mays L ◽  
Plant Density ◽  
Plant Population ◽  
Yield Response ◽  
Corn Yield ◽  
Subsequent Paper ◽  
Southern Ontario ◽  
High Plant Density

Summer dry spells in some areas of southern Ontario during the last decade have increased interest in supplemental irrigation. Field studies were conducted in a 2500 heat unit area of southern Ontario on Orthic/Brunisolic Grey Brown Luvisol soils to determine the yield response of field corn (Zea mays L.) to irrigation in midsummer when combined with increased plant density and N rates. The yield responses, phenological records and soil moisture measurements are to be used in the calibration and validation of a corn yield estimation model, to be published in a subsequent paper. Two to four irrigations were applied each year using the line method when soil moisture pressure potential reached −40 to −60 kPa at 22.5 cm depth. Development stages were unaffected by irrigation. Yield increases from irrigation were directly proportional to water applied in midsummer and the intensity of dry weather. Yields increased with plant density in 4 of the 5 yr and were usually consistent over irrigation levels. Additional nitrogen above the recommended rate increased yields in 1982 and 1983, decreased yields in 1981, and resulted in no differences the other two years. In years of positive response to extra nitrogen, there was usually a greater response with irrigation and the responses were greatest at high plant density and for the longer season hybrids. Harvest indices decreased as irrigation amount increased and were exceptionally high in 1983.Key words: Corn, Zea mays L., line-source irrigation, plant population, nitrogen, harvest index

Responses of group and individual leaf photosynthetic characteristics of two summer maize (Zea mays L.) to leaf removal under high plant density

2014 ◽  
Vol 94 (8) ◽  
pp. 1449-1459 ◽  
Author(s):  
T.-N. Liu ◽  
L.-M. Gu ◽  
C.-L. Xu ◽  
S.-T. Dong
Keyword(s):  
Zea Mays ◽  
Grain Yield ◽  
Zea Mays L ◽  
Plant Density ◽  
Photosynthetic Capacity ◽  
Photosynthetic Characteristics ◽  
Leaf Removal ◽  
Summer Maize ◽  
Individual Leaf ◽  
High Plant Density

Liu, T.-N., Gu, L.-M., Xu, C.-L. and Dong, S.-T. 2014. Responses of group and individual leaf photosynthetic characteristics of two summer maize (Zea mays L.) to leaf removal under high plant density. Can. J. Plant Sci. 94: 1449–1459. The present experiment was conducted during the growing seasons of 2012 and 2013 using two summer maize (Zea mays L.) cultivars, Zhengdan958 (a compact cultivar) and Jinhai5 (a semi-compact cultivar) grown at a plant density of 105 000 plants ha−1, to evaluate the influence of leaf removal on canopy apparent photosynthesis (CAP), individual leaf photosynthetic characteristics and grain yield. Plants were subjected to the removal of two (S1), four (S2) or six leaves (S3) from the top of the plant 3 d after anthesis (DAA), with no leaf removal as control (S0). The results of 2 yr indicated that with increased intensity of leaf removal, the transmission of light to lower strata of the canopy increased. With the removal of two leaves (S1), CAP increased and longer durations of CAP and green leaf are index were maintained during grain filling, whereas CAP in S2 and S3 treatments was inhibited and drastically declined. Generally, leaf removal appeared to stimulate an increase in the net photosynthetic rate (PN), stomatal conductance (gs) and chlorophyll content of the remaining ear leaves in S2 and S3 treatments prior to 26 DAA. Nevertheless, thereafter, plants in the S1 treatment had an advantage in terms of individual photosynthetic capacity. These results indicate that excising two leaves made plants more tolerant of high plant density due to enhanced photosynthetic capacity in ear leaves as well as a more efficient canopy structure, resulting in a better coordination of groups and individuals, and finally achieved significantly higher grain yield. In addition, relative to Zhengdan958, the effects of leaf removal on Jinhai5 were more apparent.

INFLUENCE OF PLANT DENSITY ON THE DISTRIBUTION OF 14C-LABELLED ASSIMILATE IN MAIZE AT FLOWERING

1979 ◽  
Vol 59 (3) ◽  
pp. 577-584 ◽  
Author(s):  
G. O. EDMEADES ◽  
N. A. FAIREY ◽  
T. B. DAYNARD
Keyword(s):  
Zea Mays ◽  
Zea Mays L ◽  
Plant Density ◽  
Reproductive Organs ◽  
Planting Density ◽  
Dominant Factor ◽  
Vegetative Organs ◽  
Coefficients Of Variation ◽  
Plant Densities ◽  
Lower Stem

The distribution pattern of 14C-labelled assimilate in the flowering shoot of maize (Zea mays L.) grown in the field at three plant densities (50 000, 100 000 and 150 000 plants/ha) was determined by labelling with 14CO2 at 1 day after anthesis. Shoots were harvested 4 days later. Four leaf positions were fed 14CO2 at each density; relative to the ear leaf (EL), these were EL+4 (i.e. fourth leaf above ear leaf), EL+2, EL, and EL-2. At the lowest plant density EL-4 was also labelled. The dominant factor influencing assimilate distribution was the position of the assimilating leaf rather than plant density. Assimilate from upper leaves supplied the tassel, upper stem, and ear preferentially. Assimilate from lower leaves supplied the lower stem and ear. Among leaf positions the ear leaf supplied the greatest percentage of its assimilate (26% at 50 000 plants/ha and 19% at 150 000 plants/ha) to the developing cob (rachis plus grain initials). As density increased so did the proportion of labelled assimilate remaining in labelled leaves. Coefficients of variation, computed among individual plants, indicated that assimilate distribution to reproductive organs was more variable than that to vegetative organs and that this variability increased with planting density.

Selection and Adaptation to High Plant Density in the Iowa Stiff Stalk Synthetic Maize (Zea mays L.) Population

Crop Science ◽  
2011 ◽  
Vol 51 (5) ◽  
pp. 1965-1972 ◽  
Author(s):  
Brent Brekke ◽  
Jode Edwards ◽  
Allen Knapp
Keyword(s):  
Zea Mays ◽  
Zea Mays L ◽  
Plant Density ◽  
High Plant Density
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