Heterosis and parent–progeny relationships for silk extrusion dynamics and kernel number determination in maize: Nitrogen effects

Crop Science ◽  
2020 ◽  
Vol 60 (2) ◽  
pp. 961-976
Author(s):  
María A. Rossini ◽  
Ignacio R. Hisse ◽  
María E. Otegui ◽  
Karina E. D´Andrea
Keyword(s):  
Kernel Number

Sowing Date and Maize Productivity: II. Kernel Number Determination

Crop Science ◽  
1994 ◽  
Vol 34 (4) ◽  
pp. 1044-1046 ◽  
Author(s):  
A. G. Cirilo ◽  
F. H. Andrade
Keyword(s):  
Sowing Date ◽  
Kernel Number ◽  
Maize Productivity

scholarly journals An ethylene biosynthesis enzyme controls quantitative variation in maize ear length and kernel yield

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Qiang Ning ◽  
Yinan Jian ◽  
Yanfang Du ◽  
Yunfu Li ◽  
Xiaomeng Shen ◽  
...  
Keyword(s):  
Gene Editing ◽  
Ethylene Biosynthesis ◽  
Flower Number ◽  
Kernel Number ◽  
Spikelet Number ◽  
Inflorescence Development ◽  
Grain Productivity ◽  
Trait Locus ◽  
Maize Gene ◽  
Maize Ear

AbstractMaize ear size and kernel number differ among lines, however, little is known about the molecular basis of ear length and its impact on kernel number. Here, we characterize a quantitative trait locus, qEL7, to identify a maize gene controlling ear length, flower number and fertility. qEL7 encodes 1-aminocyclopropane-1- carboxylate oxidase2 (ACO2), a gene that functions in the final step of ethylene biosynthesis and is expressed in specific domains in developing inflorescences. Confirmation of qEL7 by gene editing of ZmACO2 leads to a reduction in ethylene production in developing ears, and promotes meristem and flower development, resulting in a ~13.4% increase in grain yield per ear in hybrids lines. Our findings suggest that ethylene serves as a key signal in inflorescence development, affecting spikelet number, floral fertility, ear length and kernel number, and also provide a tool to improve grain productivity by optimizing ethylene levels in maize or in other cereals.

scholarly journals Yield component variation in winter wheat grown under drought stress

2000 ◽  
Vol 80 (4) ◽  
pp. 739-745 ◽  
Author(s):  
B. L. Duggan ◽  
D. R. Domitruk ◽  
D. B. Fowler
Keyword(s):  
Drought Stress ◽  
Winter Wheat ◽  
Grain Yield ◽  
Triticum Aestivum L ◽  
Yield Component ◽  
Yield Potential ◽  
High Yield ◽  
Crop Water ◽  
Kernel Number ◽  
High Yield Potential

Crops produced in the semiarid environment of western Canada are subjected to variable and unpredictable periods of drought stress. The objective of this study was to determine the inter-relationships among yield components and grain yield of winter wheat (Triticum aestivum L) so that guidelines could be established for the production of cultivars with high yield potential and stability. Five hard red winter wheat genotypes were grown in 15 field trials conducted throughout Saskatchewan from 1989–1991. Although this study included genotypes with widely different yield potential and yield component arrangements, only small differences in grain yield occurred within trials under dryland conditions. High kernel number, through greater tillering, was shown to be an adaptation to low-stress conditions. The ability of winter wheat to produce large numbers of tillers was evident in the spring in all trials; however, this early season potential was not maintained due to extensive tiller die-back. Tiller die-back often meant that high yield potential genotypes became sink limiting with reduced ability to respond to subsequent improvements in growing season weather conditions. As tiller number increased under more favourable crop water conditions genetic limits in kernels spike−1 became more identified with yield potential. It is likely then, that tillering capacity per se is less important in winter wheat than the development of vigorous tillers with numerous large kernels spike−1. For example, the highest yielding genotype under dryland conditions was a breeding line, S86-808, which was able to maintain a greater sink capacity as a result of a higher number of larger kernels spike−1. It appears that without yield component compensation, a cultivar can be unresponsive to improved crop water conditions (stable) or it can have a high mean yield, but it cannot possess both characteristics. Key words: Triticum aestivum L., wheat, drought stress, kernel weight, kernel number, spike density, grain yield

Intercepted Radiation at Flowering and Kernel Number in Maize: Shade versus Plant Density Effects

Crop Science ◽  
1993 ◽  
Vol 33 (3) ◽  
pp. 482-485 ◽  
Author(s):  
Fernando H. Andrade ◽  
Sergio A. Uhart ◽  
Mariano I. Frugone
Keyword(s):  
Plant Density ◽  
Kernel Number ◽  
Density Effects ◽  
Intercepted Radiation

Simulating kernel number under different water regimes using the Water-Flowering Model in hybrid maize seed production

2018 ◽  
Vol 209 ◽  
pp. 188-196 ◽  
Author(s):  
Jintao Wang ◽  
Shaozhong Kang ◽  
Xiaotao Zhang ◽  
Taisheng Du ◽  
Ling Tong ◽  
...  
Keyword(s):  
Seed Production ◽  
Maize Seed ◽  
Kernel Number ◽  
Water Regimes ◽  
Hybrid Maize

Breeding durum wheat in western Canada: Historical trends in yield and related variables

1995 ◽  
Vol 75 (1) ◽  
pp. 55-60 ◽  
Author(s):  
T. N. McCaig ◽  
J. M. Clarke
Keyword(s):  
Durum Wheat ◽  
Triticum Turgidum ◽  
Kernel Weight ◽  
Western Canada ◽  
Kernel Number ◽  
Historical Trends ◽  
Days To Maturity ◽  
Sink Demand ◽  
Over Time ◽  
Selection Of

Canadian durum wheat (Triticum turgidum L.) production is centred in the Brown and Dark Brown soil zones, areas of limited rainfall. For more than 50 yr, lines have been evaluated in the multi-location Durum Cooperative Test. Data from this test, over the period 1947–1992, were analyzed with the objectives of determining the advances that have been made within the Canada Western Amber Durum (CWAD) wheat class and comparing yield-related variables of recently registered cultivars with those of earlier cultivars. Canadian-developed cultivars have increased yields about 0.81% yr−1 relative to Hercules, or approximately 22.6 kg ha−1 yr−1. As kernel weight has remained unchanged, the genetic yield increases have resulted entirely from an increase in the number of kernels produced. Because kernel number is determined prior to, and during, anthesis, further yield increases may depend upon selection of genotypes that produce higher numbers of kernels, thereby increasing sink demand. While plant height and hectolitre weight have been decreasing over time, neither variable was significantly (P < 0.05) correlated with the yield increases that have taken place over the 29-yr period. The selection pressure toward shorter cultivars may have involved other agronomic advantages, such as decreased lodging. Days to maturity did not change significantly over time and was not correlated with yield. Key words:Triticum turgidum, kernel number, kernel weight, height, hectolitre weight

Temperature and precipitation effects on durum wheat grown in southern Saskatchewan for fifty years

1997 ◽  
Vol 77 (2) ◽  
pp. 215-223 ◽  
Author(s):  
T. N. McCaig
Keyword(s):  
Durum Wheat ◽  
Triticum Turgidum ◽  
Kernel Weight ◽  
Maximum Effect ◽  
Weather Variables ◽  
Kernel Number ◽  
Weather Factors ◽  
Brown Soil ◽  
Soil Zone ◽  
Semi Arid

Approximately 60% of Canadian durum wheat (Triticum turgidum L.) is produced in the semi-arid, Brown soil zone of southern Saskatchewan. The Durum Wheat Cooperative Test (DWCT) provides the means of evaluating potential new cultivars, and has been grown at Swift Current, located near the centre of the Brown soil zone in Saskatchewan, for more than 50 yr. Historical yield-related data from the DWCT were analyzed in conjunction with daily precipitation and maximum daily temperature (MaxDT) data with the objective of improving our understanding of the effects of these weather variables on durum wheat grown in this semi-arid region.The highest correlation between the weather variables and grain yield was during the period near the end of June through early July, approximately the time of anthesis. The correlation with kernel number m−2 (KNum) was maximum near the end of June, while the correlation with kernel weight was highest around the third week of July. The maximum effect of these weather factors in limiting yield in the Brown soil zone was through an impact on KNum around anthesis. Hectolitre weight and time-to-maturi-ty appeared to be influenced mainly by the weather in July, while crop height was determined by the weather near the end of June. An analysis which examined cumulative heat-units above threshold MaxDT of 20, 24, 28 and 32 °C indicated that temperatures >24 °C may be detrimental during early June although high temperatures are less common in June than in July. Yield was also negatively impacted by temperatures >20 °C during the first 3 wk of July.Future yield gains in this semi-arid region may be dependent upon the development of cultivars which are more tolerant of drought and high-temperature stress at anthesis. Key words: Triticum turgidum, kernel number, kernel weight, height, maturity, hectolitre weight

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

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