Potential for increasing rate of grain growth in spring wheat. I. Identification of genetic improvements

1996 ◽  
Vol 47 (1) ◽  
pp. 17 ◽  
Author(s):  
BR Whan ◽  
GP Carlton ◽  
WK Anderson
Keyword(s):  
Growth Rate ◽  
Grain Growth ◽  
Selection Criterion ◽  
Grain Filling ◽  
Kernel Weight ◽  
Slight Reduction ◽  
Growth Duration ◽  
Similar Time ◽  
Physiological Maturity ◽  
Breeding Populations

Cultivars that can fill their grain quickly may have an advantage in environments with short, hot, dry grain-filling periods, but this hypothesis needs to be tested by selecting in breeding populations. The rate and duration of grain growth of 13 introductions and three local, standard cultivars were measured in nine environments over 3 years to identify new germplasm with faster grain growth and shorter durations of grain growth. Duration of grain growth was calculated from the cumulative daily average temperatures between anthesis and physiological maturity, and rate of grain growth was calculated from the mean kernel weight and duration. The loss of green colour from the peduncle was used as an indicator of physiological maturity. The aim was to identify parents to use in a subsequent breeding program. Genotypes were identified with improvements in grain growth characters over the standard cultivars. Kansu No. 32, SA 42, NIAB 75-509 and Maya 74 had the fastest rates of grain growth, e.g. 75, 84, 79 and 70 8g/kernel �C day respectively, compared with 64 for Aroona, the best standard cultivar, at sites with short periods of grain growth. Kansu No. 32 developed heavy kernels quickly, and differed from other genotypes in that it had a short duration of grain growth that was consistent regardless of environmental conditions. SA 42, NIAB 75-509 and CEP 8058 also developed grain quickly, with the flexibility to develop grain in a shorter time than the standard cultivars in hot grain-filling conditions, but similar time in favourable conditions. These four genotypes had less kernels/m2 associated with the increased grain growth rate. Yu Mai 7, Maya 74 and V763-251 had smaller increases in rates of grain growth, but only a slight reduction in kernel numbers. Rate of grain growth is more important than duration as a selection criterion to improve kernel weight and grain yield in Western Australian conditions, as duration is influenced to a much greater extent by environment. Growth rate was negatively associated with number of kernels/m2, so these two characters must be considered simultaneously in selection, to ensure grain numbers are maintained while improving rate of grain growth.

Factors Influencing the Rate and Duration of Grain Filling in Wheat

1977 ◽  
Vol 4 (5) ◽  
pp. 785 ◽  
Author(s):  
I Sofield ◽  
LT Evans ◽  
MG Cook ◽  
IF Wardlaw
Keyword(s):  
Growth Rate ◽  
Grain Yield ◽  
Grain Growth ◽  
Dry Weight ◽  
Grain Filling ◽  
Close Relation ◽  
Grain Number ◽  
Lag Period ◽  
The Difference ◽  
Leaf Photosynthetic Rate

Controlled-environment conditions were used to examine the effects of cultivar and of temperature and illuminance after anthesis on grain setting and on the duration and rate of grain growth. After an initial lag period, which did not differ greatly between cultivars, grain dry weight increased linearly under most conditions until final grain weight was approached. Growth rate per grain depended on floret position within the ear, varied between cultivars (those with larger grains at maturity having a faster rate), and increased with rise in temperature. With cultivars in which grain number per ear was markedly affected by illuminance, light had relatively little effect on growth rate per grain. With those in which grain number was less affected by illuminance, growth rate per grain was highly responsive to it, especially in the more distal florets. In both cases there was a close relation between leaf photosynthetic rate as influenced by illuminance, the rate of grain growth per ear, and final grain yield per ear. The duration of linear grain growth, on the other hand, was scarcely influenced by illuminance, but was greatly reduced as temperature rose, with pronounced effects on grain yield per ear. Cultivars differed to some extent in their duration of linear growth, but these differences accounted for less of the difference in final weight per grain than did those in rate of grain growth. Under most conditions the cessation of grain growth did not appear to be due to lack of assimilates.

scholarly journals Effect of seed priming on grain growth rate and effective filling period in bread wheat (Triticum aestivum L.) cultivars

2018 ◽  
Author(s):  
H.K.M.A. Al-Haidary ◽  
S.K. Al-Taweel ◽  
J.H. Hamza ◽  
M.H.K. Al-Baldawi
Keyword(s):  
Growth Rate ◽  
Grain Yield ◽  
Grain Growth ◽  
Bread Wheat ◽  
Block Design ◽  
Water Extract ◽  
Ethanolic Extract ◽  
Seed Priming ◽  
Water Control ◽  
Physiological Maturity

A field experiment was conducted during winter, 2015-16 with the objective to investigate the effect of bread wheat cultivars (Abu-Ghraib3, Ibaa99, and Alfeteh) and seed priming 100, 100, 150 mg L-1 of benzyl adenine, salicylic acid, gibberellic acid (GA3), respectively, ethanolic extract of Salix Sp., water extract of Glycyrrhiza glabra and distilled water (control) on grain growth rate (GGR), effective filling period (EFP) and accelerating of physiological maturity. Randomized complete block design with three replicates was applied. GA3×Ibaa99 surpassed others in grain yield (7.432 tonne ha-1) when gave the highest grain weight (45.13 mg grain-1) and GGR (1.5 mg grain-1 day-1) with the fastest time to start and end EFP (5 and 34 days), which mean it reached to physiological maturity earlier. It can be conclude that seed priming led to accelerating the physiological maturity with increase grain yield through enhancing GGR and EFP in bread wheat.

scholarly journals The influence of temperature and light intensity on grain growth in relation to the carbohydrate and nitrogen economy of the wheat plant.

1977 ◽  
Vol 25 (3) ◽  
pp. 182-197 ◽  
Author(s):  
J.H.J. Spiertz
Keyword(s):  
Growth Rate ◽  
Light Intensity ◽  
Grain Growth ◽  
Starch Synthesis ◽  
Wheat Plant ◽  
Initial Growth ◽  
Wheat Grain ◽  
Growth Duration ◽  
N Content ◽  
Influence Of Temperature

The response of wheat grain growth to temp. and light intensity was studied under controlled conditions within the ranges 10-25 deg C and 64-188 W/m2, resp. Warmth hastened plant senescence and enhanced the initial growth rate of the grains. Additional light promoted the rate of grain growth more at high than at low temp.; under the latter conditions there was a considerable accumulation of carbohydrates in the stem (up to 40%) from anthesis onwards. The rate of grain growth ranged from 0.70 to 1.64 mg/day grain. The duration of grain growth was prolonged by decrease from 25 to 10 deg ; the increase in growth duration from about 30 to 80 days corresponded with a relatively stable temp. sum. Temp. and light also affected the redistribution of assimilates and the chemical composition of the grain. The rate of protein synthesis was promoted more by warmth than the rate of starch synthesis. This resulted in an increased N content of the grain. The final content of total non-structural carbohydrates (starch and sugars) was slightly decreased by warmth. Additional light raised the carbohydrate content of all parts of the plant and so decreased the N content of these parts. However, light intensity had less effect on N distribution and yield than temp. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Ear branching as a means of increasing grain uniformity in wheat

1972 ◽  
Vol 23 (4) ◽  
pp. 551 ◽  
Author(s):  
HM Rawson ◽  
KN Ruwali
Keyword(s):  
Growth Rate ◽  
Light Intensity ◽  
Grain Growth ◽  
Growth Rates ◽  
Grain Filling ◽  
Size At Maturity ◽  
Grain Number ◽  
Photosynthetic System ◽  
Temperature Changes ◽  
The Relationship

Grain growth was compared in two field-grown wheats, Kalyan Sona, a high-yielding, seinidwarf line with few spikelets per ear and many grains per spikelet, and a branched-eared cultivar with many spikelets, each with few grains. The basis of comparison was the spikelet in Kalyan Sona and the branch in the branched material. Within the central spikelets of the main ear in Kalyan Sona, grain growth rates for the greater part of filling were b > a = c > d > e; final weights per grain for these florets were 42, 40, 37,26, and 12 mg respectively. The gradation in growth rate for the eight grains along the branch in the branched-eared cultivar was relatively small with the consequence that all grains were similar in size at maturity (range 39–43 mg); peak growth rates for all positions were at least as high as for grains a, b, and c in Kalyan Sona. In another cultivar, Triple Dirk, increasing competition for assimilates by reducing the light intensity during grain filling had a differential effect on grains within the spikelet but scarcely on the pattern between spikelets. The relationship between all grains was unaffected by temperature changes. The results are discussed in relation to competition for assimilates between grains, and the suggestion made that a high number of grains per spikelet may not use the available assimilates most efficiently. Ear branching is proposed as a preferable alternative, as this also provides abundant grain sites to utilize assimilates to the potential of the photosynthetic system, yet ensures grain uniformity per ear, regardless of grain number, by having few grains in each spikelet.

scholarly journals Effects of nitrogen on crop development and grain growth of winter wheat in relation to assimilation and utilization of assimilates and nutrients.

1978 ◽  
Vol 26 (2) ◽  
pp. 210-231 ◽  
Author(s):  
J.H.J. Spiertz ◽  
J. Ellen
Keyword(s):  
Winter Wheat ◽  
Grain Yield ◽  
Grain Growth ◽  
Grain Filling ◽  
Growth And Yield ◽  
Growth Duration ◽  
Crop Development ◽  
Grain Filling Period ◽  
Growing Conditions ◽  
High Level

Grain growth and yield components of winter wheat cv. Lely were studied in a field experiment in 1976 with 4 rates of N (50, 100, 100 + 50 or 100 + 100 kg N/ha). Growing conditions were characterized by a high level of solar radiation, warmth, ample nutrient supply and no damage by diseases. N raised grain number/m2 from 16 700 to 20 600 and grain yield from 640 to 821 g dry wt./m2. Grain growth duration was short, due to warmth, but the rate of the grain filling was very high (from 24.0 to 29.2 g/m2 day during the effective grain-filling period). A high grain yield was associated with a high grain N content which resulted in a grain protein yield ranging from 63.8 to 107.1 g/m2 with increased N rate from 50 to 200 kg/ha. The carbohydrate demand of the grains was provided by current photosynthesis and relocation of stem reserves. The latter was reflected in a decline of the stem wt. after the mid-kernel filling stage. N and P demands of the grains were supplied by withdrawal from the vegetative organs (leaves, stem, chaff) and to a large extent by post-floral uptake and assimilation. Under the prevailing growing conditions the grains turned out to be very strong sinks for carbohydrate, N and P as shown by the harvest indices. Additional N dressings increased the harvest indices of DN, N and P from 0.40 to 0.48, from 0.75 to 0.81 and from 0.91 to 0.93 resp. It was suggested that a more restricted vegetative crop development at high N levels and a longer duration of root activity, photosynthesis and grain growth after anthesis would considerably favour grain yield. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Growth and yield of highland maize in Mexico

1974 ◽  
Vol 83 (2) ◽  
pp. 213-221 ◽  
Author(s):  
P. R. Goldsworthy ◽  
M. Colegrove
Keyword(s):  
Growth Rate ◽  
Grain Growth ◽  
Growth Rates ◽  
Dry Weight ◽  
Grain Filling ◽  
Growth And Yield ◽  
Weight Changes ◽  
Highland Maize ◽  
Grain Filling Period ◽  
Tropical Varieties

SUMMARYThe growth and yield of five highland varieties of tropical maize were studied. Grain yields were between 4·7 and 8·8 t/ha. Crop growth rates (C) increased to a maximum of between 25 and 35 g/m2/day at silking and then declined. Grain growth rates (maximum 21 g/m2/day) exceeded current C during most of the grain-filling period.After silking, when C exceeded grain growth rate, dry matter accumulated in the stem and husk, resulting in an increase of from 200 to 600 g/m2. Later, as grain growth rate increased and exceeded current C, some of this accumulated material was incorporated into the grain, and stem weight decreased. A comparison of the dry weight changes after flowering in these varieties with those reported for a hybrid that yielded 12 t grain/ha indicates that the smaller yield of the Mexican varieties was associated with smaller grain growth rates and the incorporation into the grain of a smaller fraction of the dry weight produced after flowering. These results suggest that the capacity of the grain ‘sink’ to utilize assimilates limited yields in the tropical varieties.

Genotypic diversity in sorghum inbred lines for grain-filling patterns and other related agronomic traits

2011 ◽  
Vol 62 (12) ◽  
pp. 1026 ◽  
Author(s):  
Brenda L. Gambín ◽  
Lucas Borrás
Keyword(s):  
Growth Rate ◽  
Grain Growth ◽  
Agronomic Traits ◽  
Grain Filling ◽  
Inbred Lines ◽  
Degree Days ◽  
Grain Number ◽  
Trade Off ◽  
Maximum Water ◽  
Maximum Water Content

Opportunities for genetic improvement on specific traits require information on available diversity, together with knowledge on heritability estimates and possible trade-off relations among traits. Sixty-five sorghum inbred lines were evaluated for grain filling and other agronomic traits during 2008 and 29 re-evaluated in 2009. Time to anthesis, final grain weight (GW), grain growth rate, duration of grain filling, maximum water content, grain desiccation rate, moisture concentration at physiological maturity, plant height, panicle length, grain number per plant and final yield per plant were measured both years. Results highlighted the available variability for grain-filling patterns in sorghum, and genotypic differences (P < 0.05) for all traits were evident. Final GW variation (16–44 mg grain–1 in 2008, and 20–40 mg grain–1 in 2009) was achieved through different combinations of rate (3.27–9.78 mg degree-days grain–1 10−2) and duration of grain filling (413–853 degree-days). Calculated heritability for grain-filling traits ranged from 0.43 to 0.95, showing GW and maximum water content had the highest values. Grain number showed consistent negative associations with grain growth rate but not with GW due to grain-filling duration variability. This suggests selecting longer grain filling can increase GW (and yield) without negative trade-off relations with grain number.

A Model of Wheat Grain Growth and Its Applications to Different Temperature and Carbon Dioxide Levels

1995 ◽  
Vol 22 (5) ◽  
pp. 843 ◽  
Author(s):  
YP Wang ◽  
RM Gifford
Keyword(s):  
Growth Rate ◽  
Grain Growth ◽  
Temperature Response ◽  
Rate Sensitivity ◽  
Temperature Sensitive ◽  
Potential Growth ◽  
Carbon Supply ◽  
The Difference ◽  
Carbon Dioxide Levels ◽  
Kernel Growth

Kernel growth after anthesis is simulated as a function of the potential kernel growth rate, current photosynthate production and mobilisation of stored reserves. The potential growth rate of the kernel is simulated as two temperature-sensitive processes, cell production and cell growth. The difference between the potential and actual growth rates of the kernel depends on the carbon supply to the free space of the kernel endosperm, while the carbon supply is itself affected by the actual kernel growth rate. Sensitivity analysis showed that the growth rate of the grain per plant is most sensitive to the potential growth rate of the kernel and number of kernels per plant. This model is able to simulate the observed rates of grain growth and leaf senescence from anthesis to physiological maturity for wheat plants grown in two CO2 concentrations. The simulated temperature response of grain growth agrees well with the experimenal observations.

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

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