CO2-fixation enzymes in maize (Zea mays) and grain yield

1987 ◽  
Vol 65 (3) ◽  
pp. 607-611 ◽  
Author(s):  
Herminia Loza-Tavera ◽  
Bernardo Serrano ◽  
José D. Molina ◽  
Ma. Luisa Ortega-Delgado ◽  
Estela Sanchez-de-Jiménez
Keyword(s):  
Zea Mays ◽  
Grain Yield ◽  
Co2 Fixation ◽  
Grain Filling ◽  
Mass Selection ◽  
Bisphosphate Carboxylase ◽  
Maize Variety ◽  
Selection For ◽  
Grain Filling Period ◽  
Agronomical Traits

Maize variety Zacatecas 58 (Z0), was used to select, after 12 cycles of mass selection for grain yield, an improved population (Z12). Some agronomical traits were characterized at the end of the selected period in both populations. Ribulose-1,5-bisphosphate carboxylase–oxygenase (RuBPcase) activity, phosphoenolpyruvate carboxylase (PEPcase) activity, protein content, and chlorophyll content were measured in the leaves above the ear, throughout the grain filling period (from anthesis to 40 days afterwards). Various agronomical traits associated with increase in yield, such as length and diameter of ear, rows per ear, and kernels per row, were greater in the Z12 than in the Z0 population. Likewise, the Z12 population showed 50% more yield than Z0, although days to anthesis did not increase significantly. During the grain filling period the leaves of the Z12 population had more activity of RuBPcase but not PEPcase compared with the Z0 population. It is suggested that the higher level of RuBPcase activity observed in the Z12 population might be related to its improved grain yield.

PERFORMANCE UNDER STRESS OF ADVANCED CYCLES OF FOUR POPULATIONS OF CORN (Zea mays L.) IN AN S1 PER SE RECURRENT SELECTION PROGRAM

1981 ◽  
Vol 61 (1) ◽  
pp. 29-36
Author(s):  
O. A. ADARA ◽  
L. W. KANNENBERG
Keyword(s):  
Zea Mays ◽  
Grain Yield ◽  
Recurrent Selection ◽  
Zea Mays L ◽  
Selection Criterion ◽  
Grain Filling ◽  
Primary Selection ◽  
Per Se ◽  
Selection For ◽  
Advanced Cycles

Two cycles of S1 per se recurrent selection were conducted in four populations of corn (Zea mays L.). The primary selection criterion was a performance index: grain yield divided by percent moisture at harvest. The original (C0) source material and first cycle (C1) of selection for each population were evaluated in a favorable (1977) and an unfavorable (1978) growing season. Second cycle (C2) materials were also included in the 1978 comparisons. In 1977, C1 yielded significantly more grain than C0 in three of the four populations. In contrast, performance of C1 and C2 materials in 1978 was inferior to C0 in all populations but one. The advanced cycles of only one population showed improvement over C0 in both years. Comparisons of the 1977 data for days to silking, grain yield, and percent ear moisture at harvest suggest that rate of grain filling in C1 was higher than in C0 for all populations. The higher rates of grain filling in the advanced cycles may have caused a carbohydrate deficiency under stress (1978) so that the leaves no longer functioned normally and kernel filling was terminated prematurely. In general, the four populations showed inherent differences in their respective responses to selection, to environmental stress, and to inbreeding.

EFFECTS OF PHOTOPERIOD AND TEMPERATURE ON VEGETATIVE AND REPRODUCTIVE GROWTH OF A MAIZE (ZEA MAYS) HYBRID

1977 ◽  
Vol 57 (4) ◽  
pp. 1127-1133 ◽  
Author(s):  
R. B. HUNTER ◽  
M. TOLLENAAR ◽  
C. M. BREUER
Keyword(s):  
Zea Mays ◽  
Grain Yield ◽  
Dry Weight ◽  
Grain Filling ◽  
Temperature Treatment ◽  
Limiting Factor ◽  
Grain Filling Period ◽  
Temperature Interaction ◽  
Lower Temperature ◽  
Vegetative And Reproductive Growth

A single-cross maize (Zea mays L.) hybrid was grown to maturity in the four combinations of two temperatures, 20 and 30 C, and two photoperiods, 10 and 20 h, in controlled-environment growth cabinets. Measurements of dry weights of plant components were made at tassel initiation, mid-anthesis, mid-anthesis plus 16 days, and maturity. The longer photoperiod and cooler temperature treatment produced the highest final plant dry weight. Average daily dry matter (DM) production was greater for plants grown at the longer photoperiod. This could largely be attributed to a higher leaf area per plant. The duration of DM production was longer at the cooler temperature. Grain yields were higher under the lower temperature because of an increase in the length of the grain-filling period and because a greater proportion of the post-anthesis DM was allocated to the grain. The results of this study showed a significant photoperiod × temperature interaction for length of the grain-filling period, kernel number and grain yield. Post-anthesis DM accumulation did not appear to be a limiting factor for grain yield. The effects of temperature and photoperiod on length of the grain-filling period and grain yield may have been partly mediated through the size of the grain sink.

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

scholarly journals Effects of Drought Stress on Some Agronomic and Morpho-Physiological Traits in Durum Wheat Genotypes

2020 ◽  
Vol 12 (14) ◽  
pp. 5610
Author(s):  
Alireza Pour-Aboughadareh ◽  
Reza Mohammadi ◽  
Alireza Etminan ◽  
Lia Shooshtari ◽  
Neda Maleki-Tabrizi ◽  
...  
Keyword(s):  
Drought Stress ◽  
Grain Yield ◽  
Durum Wheat ◽  
Harvest Index ◽  
Plant Biomass ◽  
Geometric Mean ◽  
Grain Filling ◽  
Tolerance Index ◽  
Wheat Genotypes ◽  
Grain Filling Period

Durum wheat performance in the Mediterranean climate is limited when water scarcity occurs before and during anthesis. The present research was performed to determine the effect of drought stress on several physiological and agro-morphological traits in 17 durum wheat genotypes under two conditions (control and drought) over two years. The results of analysis of variance indicated that the various durum wheat genotypes responded differently to drought stress. Drought stress significantly reduced the grain filling period, plant height, peduncle length, number of spikes per plot, number of grains per spike, thousand grains weight, grain yield, biomass, and harvest index in all genotypes compared to the control condition. The heatmap-based correlation analysis indicated that grain yield was positively and significantly associated with phenological characters (days to heading, days to physiological maturity, and grain filling period), as well as number of spikes per plant, biomass, and harvest index under drought conditions. The yield-based drought and susceptible indices revealed that stress tolerance index (STI), geometric mean productivity (GMP), mean productivity (MP), and harmonic mean (HM) were positively and significantly correlated with grain yields in both conditions. Based on the average of the sum of ranks across all indices and a three-dimensional plot, two genotypes (G9 and G12) along with the control variety (G1) were identified as the most tolerant genotypes. Among the investigated genotypes, the new breeding genotype G12 showed a high drought tolerance and yield performance under both conditions. Hence, this genotype can be a candidate for further multi-years and locations test as recommended for cultivation under rainfed conditions in arid and semi-arid regions.

Dry matter accumulation and partitioning and its relationship to grain yield in wheat

1995 ◽  
Vol 35 (4) ◽  
pp. 495 ◽  
Author(s):  
RG Flood ◽  
PJ Martin ◽  
WK Gardner
Keyword(s):  
Grain Yield ◽  
Dry Matter ◽  
Grain Filling ◽  
Dry Matter Accumulation ◽  
The North ◽  
Similar Range ◽  
Total Crop ◽  
Grain Filling Period ◽  
Stem Reserves ◽  
North Western

Total crop dry matter (DM) production and its components, remobilisation of stem reserves, and the relation of these to grain yield were studied in 10 wheat cultivars sown at Walpeup, Boort, and Horsham in the north-western Victorian wheatbelt. Between sites, all DM components decreased in the order Horsham > Boort > Walpeup. Differences between Boort and Walpeup were not always significant. Total DM at anthesis for Walpeu,p and Boort was in a similar range, and less than that for Horsham. Yields increased in the order Walpeup < Boort < Horsham. When data from the 3 sites were combined, leaf, stem (excluding cv. Argentine IX), and total DM were related to grain yield. Within sites, ear DM at anthesis was related to grain yield. Grain yield for all cultivars at Horsham and Walpeup and 5 cultivars at Boort was greater than the increases in crop DM from anthesis to maturity, indicating that pre-anthesis stored assimilates (stem reserves) were used for grain filling. Post-anthesis decrease in stem weight was inversely related to grain yield only at Horsham, which supports the view of utilisation of stem reserves for grain filling at this site. At Boort and Walpeup there was a similar negative trend, but values for 2 cultivars at each site were outliers, which weakened the trend. The wide adaptability of the Australian cultivars used in this study may be related to the differential remobilisation of stem reserves at each site. A measure of yield stability, however, was not related to stem weight loss during the grain-filling period.

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