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

R-nj ALEURONE COLOR SELECTION AND NITROGEN RESPONSE IN OPAQUE-2 MAIZE

1989 ◽  
Vol 69 (3) ◽  
pp. 741-747
Author(s):  
H. Z. CROSS ◽  
H. DOSSO
Keyword(s):  
Field Experiments ◽  
Agronomic Traits ◽  
Seedling Emergence ◽  
Kernel Weight ◽  
Low Fertility ◽  
Correlated Response ◽  
Mass Selection ◽  
Nitrogen Response ◽  
Color Selection ◽  
Selection For

Field experiments were conducted to determine if mass selection for degree of aleurone anthocyanin pigmentation controlled by R-nj could improve agronomic deficiencies associated with the o2 (opaque) phenotype of a maize (Zea mays L.) synthetic (NDSE). Divergent mass selection was used to develop high color (HC), low color (LC), and randomly sampled (RC) check substrains which were tested in 1982 at two low-fertility, pollen isolated sites (a clay loam, Vertic Haplaquoll with 7.2 pH and a silt loam, Aerie Calciaquoll with a 7.6 pH at Fargo and Casselton, N.D., respectively). Grain yield and agronomic traits were estimated for each of four N application rates at each site. N fertilizer increased grain yields and kernel weights. High color strains yielded highest at 136 kg ha−1 of N, outproducing RC strains. At 204 kg ha−1 of N, yield of HC strains declined and LC strains out-yielded HC strains. Low color selection significantly increased test weight, kernel weight, cob diameter, seedling emergence, and shelling ratio compared to RC strains in NDSE while HC selection increased kernel weight, cob diameter, and reduced ear moisture and protein contents compared to RC selection. Selection for LC improved several traits which were deficient in opaque-2 maize, and use of the R-nj gene may be useful in improving opaque-2 maize.Key words: Aleurone, anthocyanin, correlated response, ear moisture, mass selection, maize.

Ear moisture during kernel development as influenced by field and laboratory selection

1995 ◽  
Vol 75 (3) ◽  
pp. 557-563 ◽  
Author(s):  
H. Z. Cross
Keyword(s):  
Moisture Content ◽  
Field Study ◽  
Agronomic Traits ◽  
Grain Filling ◽  
Kernel Weight ◽  
Test Weight ◽  
Mass Selection ◽  
Dry Matter Accumulation ◽  
Drying Characteristics ◽  
Laboratory Selection

Grain quality, timeliness of harvest, and profitability can be increased by improving field drying characteristics of maize (Zea mays L.) hybrids. To better understand hows genes control ear drying, I compared maize strains developed by divergently selecting three cycles for (1) high HM or low LM moisture content at 45 d post pollination in the field or (2) fast FD vs. slow ear drying SD In laboratory. A field study across five locations compared HM, LM, FD, and SD strains from each of five synthetics for grain yield, ear moisture at harvest, test weight, lodging, and other agronomic traits. I studied ear moisture during grain filling for two subsets of divergently selected strains from one and three synthetics for 2 yr. In a third 2-yr field study, I measured mature kernel weight, lag period duration (LPD), effective grain-filling period (EFPD), and rate of dry matter accumulation (RDMA) for LM and HM strains developed from each of four synthetics. When averaged across the five synthetics, both SD and LM selections produced equivalent yields but lower ear moisture at harvest than the corresponding divergent strains. The LM strains had higher test weights than HM strains. When averaged across three synthetics and 2 yr, the HM strains produced higher moisture than LM strains at 15, 30, 45, and 60 d after silking. However, environments also influenced moisture content of the kernels during grain filling. In three of the four synthetics studied, HM strains had heavier kernels than corresponding LM strains. The heavier kernels seem to be due to increased RDMA. When averaged across four synthetics, LM strains had shorter LPD than HM strains. These correlated selection responses suggest that a genetic association exists among moisture content during grain filling, moisture content at physiological maturity, moisture content at harvest, LPD, and test weight. Breeding for LM or SD should improve field-drying characteristics of maize without increasing stalk breakage or decreasing yields. Key words:Zea mays L., grain filling, dry-down rates, mass selection, breeding methods

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.

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.

THE INFLUENCE OF WATER AVAILABILITY ON WINTER WHEAT YIELDS

1982 ◽  
Vol 62 (4) ◽  
pp. 831-838 ◽  
Author(s):  
R. C. JOHNSON ◽  
E. T. KANEMASU
Keyword(s):  
Winter Wheat ◽  
Soil Water ◽  
Field Experiments ◽  
Grain Filling ◽  
Triticum Aestivum L ◽  
Kernel Weight ◽  
Additional Treatment ◽  
Treatment Regimes ◽  
Influence Of Water ◽  
Soil Water Conditions

Field experiments were conducted comparing yield and yield components of winter wheat (Triticum aestivum L.) grown under different soil water conditions. Soil water was controlled by excluding precipitation from a 150-m2 plot area with an automatic rain shelter. Treatment regimes were described according to their relative preanthesis/postanthesis soil water content as high/high (H/H), high/low (H/L), and low/high (L/H) in 1978–1979; an additional treatment, low/low (L/L) was added in 1979–1980. A neutron probe was used to periodically monitor soil water to the 150-cm depth in each regime. Plot yields ranged from 559 g/m2 in regime H/H (1978–1979) to 267 g/m2 in L/L (1979–1980) and were positively correlated with head number per square metre (r = 0.70) and kernel number per head (r = 0.79). Low preanthesis soil water reduced head number per square metre in both years. Regimes L/H and L/L in 1979–1980, which averaged the lowest preanthesis soil water of all regimes both years, had reduced kernels per spikelet compared to regimes with high preanthesis soil water. Increased kernel weight. associated with postanthesis irrigations, generally was not enough to compensate fully for fewer kernels per square metre associated with low preanthesis soil water. The results indicate that, if drought develops before grain filling in the spring, improved tiller survival and/or floret fertility could increase yields, even if some stress continued through grain filling. Under nonstress conditions, yield appears limited most by the amount of assimilate required to fill a high number of kernels per square metre.

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.

scholarly journals Barley response to seeding date in central Alberta

2003 ◽  
Vol 83 (2) ◽  
pp. 275-281 ◽  
Author(s):  
P. E. Juskiw ◽  
J. H. Helm
Keyword(s):  
Hordeum Vulgare ◽  
Grain Yield ◽  
Grain Filling ◽  
Kernel Weight ◽  
Seeding Rate ◽  
Hordeum Vulgare L ◽  
Vegetative Period ◽  
Seeding Date ◽  
The Mean ◽  
Grain Filling Period

Seeding date is an important factor influencing productivity of barley (Hordeum vulgare L.). When conditions are conducive to early seeding or result in delayed seeding, producers need to know how cultivars will respond to these seeding situations. In this study, five cultivars (Abee, Harrington, Jackson, Noble and Virden) registered for western Canada were studied for 4 yr (1990 to 1993) when seeded early (late April or early May), in mid-May, in late-May, or late (mid-June) at Lacombe, AB. For all cultivars, early seeding resulted in grain yield advantages of 113 to 134% of the mean site yield, while with late seeding, grain yields were reduced to 54 to 76% of the mean site yield. The reduction in yield was least for Jackson, the earliest maturing cultivar tested. Late seeding reduced the period from sowing to emergence, vegetative period, grain-filling period, time from emergence to physiological maturity, test weight, grain yield, kernel weight, and tillers per plant; and increased plant height and percent thins. Late seeding had no significant effect on phyllochron, stand establishment, scald, lodging, protein content of the grain, kernel number per spike, and spikelet number per spike. Barley responded positively to early seeding in central Alberta, but when seeding was delayed (in this study to mid-June) the early and mid-maturing six-rowed cultivars with short phyllochrons performed better than the two-rowed and late six-rowed cultivars. Key words: Hordeum vulgare L., seeding rate, phenological development, grain quality, grain yield, components

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

Growth of spring barley under drought: crop development, photosynthesis, dry-matter accumulation and nutrient content

1981 ◽  
Vol 96 (1) ◽  
pp. 167-186 ◽  
Author(s):  
D. W. Lawlor ◽  
W. Day ◽  
A. E. Johnston ◽  
B. J. Legg ◽  
K. J. Parkinson
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Dry Matter ◽  
Spring Barley ◽  
Grain Filling ◽  
Dry Matter Accumulation ◽  
Area Index ◽  
Water Deficits ◽  
Maximum Value ◽  
Grain Filling Period

SUMMARYThe effects of water deficit on growth of spring barley were analysed under five irrigation treatments. One crop was irrigated at weekly intervals from emergence throughout the growing season, and one was not irrigated at all after emergence. Soil water deficits in the other treatments were allowed to develop early, intermediate or late in the crop's development.Weekly irrigation produced a crop with a large leaf area index (maximum value 4) and maintained green leaf and awns throughout the grain-filling period. Early drought decreased leaf area index (maximum value 2) by slowing expansion of main-stem leaves and decreasing the number and growth of tiller leaves. Leaf senescence was also increased with drought. Drought late in the development of ears and leaves and during the grain-filling period caused leaves and awns to senesce so that the total photosynthetic areas decreased faster than with irrigation. Photosynthetic rate per unit leaf area was little affected by drought so total dry-matter production was most affected by differences in leaf area.Early drought gave fewer tillers (550/m2) and fewer grains per ear (18) than did irrigation (760 tillers/m2 and 21 grains per ear). Late irrigation after drought increased the number of grains per ear slightly but not the number of ears/m2. Thus at the start of the grain-filling period crops which had suffered drought early had fewer grains than irrigated (9·5 and 18·8 × 103/m2 respectively) or crops which suffered drought later in development (14 × 103/m2).During the first 2 weeks of filling, grains grew at almost the same rate in all treatments. Current assimilate supply was probably insufficient to provide this growth in crops which had suffered drought, and stem reserves were mobilized, as shown by the decrease in stem mass during the period. Grains filled for 8 days longer with irrigation and were heavier (36–38 mg) than without irrigation (29–30 mg). Drought throughout the grainfilling period after irrigation earlier in the season resulted in the smallest grains (29 mg).Grain yield depended on the number of ears, the number of grains per ear and mass per grain. Early drought decreased tillering and tiller ear production and the number of grains that filled in each ear. Late drought affected grain size via the effects on photosynthetic surface area.Drought decreased the concentrations of phosphorus, potassium and magnesium in the dry matter of crops, and irrigation after drought increased them. Concentration of nitrogen was little affected by treatment. Possible mechanisms by which water deficits and nutrient supply affect crop growth and yield are discussed.

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