scholarly journals Genetic Mechanisms Determining Grain Number Distribution Along the Spike and Their Effect on Yield Components in Wheat

2021 ◽  
Author(s):  
Nobuyuki Mizuno ◽  
Goro Ishikawa ◽  
Hisayo Kojima ◽  
Makoto Tougou ◽  
Chikako Kiribuchi-Otobe ◽  
...  
Keyword(s):  
Complex Trait ◽  
Apical Part ◽  
High Yield ◽  
Grain Number ◽  
Favorable Alleles ◽  
Grain Number Per Spike ◽  
Days To Heading ◽  
Causal Genes ◽  
Effect On Yield ◽  
Underlying Mechanisms

Abstract The number of wheat grains is one of the major determinant of yield. Many quantitative trait loci (QTLs) and some causal genes such as GNI-A1 and WAPO-A1 that are associated with grain number per spike (GNS) have been identified, but the underlying mechanisms remain largely unknown. We analyzed QTLs for grain number and other related traits using 188 doubled haploid lines derived from the Japanese high-yield variety, Kitahonami, as a parent to elucidate the genetic mechanism determining grain number. The major QTLs for grain number at the apical, central and basal parts of the spike were identified in different chromosomal regions. We considered GNI-A1 and WAPO-A1 as candidate genes controlling grain number at the central and basal parts of the spike, respectively. Kitahonami had the favorable 105Y allele of GNI-A1 and WAPO-A1b allele, and unfavorable alleles of QTLs for grain number at the apical part of spikes. Pyramiding the favorable alleles of these QTLs significantly increased GNS without significantly reducing thousand-grain weight (TGW). In contrast, the accumulation of favorable alleles of QTLs for TGW significantly decreased GNS, whereas days to heading positively correlated with GNS. Late heading increased the spikelet number per spike, resulting in a higher GNS. Pyramiding of the QTLs for TGW and days to heading also altered the GNS. In conclusion, GNS is a complex trait controlled by many QTLs, and it is essential for breeding to design.

scholarly journals Evolutionary and ecological perspectives on the wheat phenotype

2021 ◽  
Vol 288 (1958) ◽  
pp. 20211259
Author(s):  
Victor O. Sadras
Keyword(s):  
Precision Agriculture ◽  
Current Model ◽  
Crop Improvement ◽  
Wheat Yield ◽  
High Yield ◽  
Striking Similarity ◽  
Stabilizing Selection ◽  
Grain Number ◽  
Offspring Number ◽  
Trade Offs

Technologies, from molecular genetics to precision agriculture, are outpacing theory, which is becoming a bottleneck for crop improvement. Here, we outline theoretical insights on the wheat phenotype from the perspective of three evolutionary and ecologically important relations—mother–offspring, plant–insect and plant–plant. The correlation between yield and grain number has been misinterpreted as cause-and-effect; an evolutionary perspective shows a striking similarity between crop and fishes. Both respond to environmental variation through offspring number; seed and egg size are conserved. The offspring of annual plants and semelparous fishes, lacking parental care, are subject to mother–offspring conflict and stabilizing selection. Labile reserve carbohydrates do not fit the current model of wheat yield; they can stabilize grain size, but involve trade-offs with root growth and grain number, and are at best neutral for yield. Shifting the focus from the carbon balance to an ecological role, we suggest that labile carbohydrates may disrupt aphid osmoregulation, and thus contribute to wheat agronomic adaptation. The tight association between high yield and low competitive ability justifies the view of crop yield as a population attribute whereby the behaviour of the plant becomes subordinated within that of the population, with implications for genotyping, phenotyping and plant breeding.

scholarly journals Expected genetic advance for thousand grain weight and grain number per spike of bread wheat and durum wheat

2016 ◽  
Vol 61 (2) ◽  
pp. 113-125
Author(s):  
Gordana Brankovic ◽  
Dejan Dodig ◽  
Desimir Knezevic ◽  
Vesna Kandic ◽  
Jovan Pavlov
Keyword(s):  
Durum Wheat ◽  
Bread Wheat ◽  
Yield Component ◽  
Grain Weight ◽  
Phenotypic Variance ◽  
Environment Interaction ◽  
Genetic Advance ◽  
Thousand Grain Weight ◽  
Grain Number ◽  
Grain Number Per Spike

The research was aimed at examining variability, variance components, broadsense heritability (h2), expected genetic advance of thousand grain weight (TGW) and grain number per spike (GNS) of 15 genotypes of bread wheat and 15 genotypes of durum wheat. Field trials were carried out during 2010-2011 and 2011-2012 growing seasons at the three sites: Rimski Sancevi, Zemun Polje and Padinska Skela. Results of this investigation showed that the genetic component of variance (?2 g) was predominant for TGW of bread and durum wheat and for GNS of bread wheat. The genotype ? environment interaction (?2 ge) component of phenotypic variance was 8.72 times higher than ?2 g for GNS of durum wheat and pointed to the greater instability of durum wheat genotypes. h2 was very high (>90%) for TGW and GNS of bread wheat, high for TGW of durum wheat - 87.3% and low for GNS of durum wheat - 39.5%. Considering the high values obtained for h2 - 96.4% and the highest value for expected genetic advance as percent of mean (GAM) - 19.3% for TGW of bread wheat, the success of selection for desired values of this yield component can be anticipated. The success of selection cannot be predicted for GNS of durum wheat due to low values obtained for h2 and GAM of 39.5% and 2.8%, respectively.

scholarly journals Evaluation of nitrogen (Urea) on Zea mays L. under Balkh province climate

2020 ◽  
Vol 3 (1) ◽  
pp. 6-9
Author(s):  
Nasratullah Habibi ◽  
Friba Sikandari
Keyword(s):  
Zea Mays ◽  
Nitrogen Fertilizer ◽  
Yield Components ◽  
Zea Mays L ◽  
Agricultural Research ◽  
Block Design ◽  
High Yield ◽  
Randomized Complete Block Design ◽  
Yield And Yield Components ◽  
Effect On Yield

An experiment was conducted to evaluate effect of urea fertilizer on yield and yield components of Zea mays L. Using Randomized Complete Block Design (RCBD) split plots in three replications in agricultural research farm of Balkh University by 2019. Doses of urea used in this experiment were 0, 80, 160 and 240 kg ha-1 , respectively. It has been found that amount of nitrogen fertilizer (urea) had significant effect on yield of maize at p<0.05. The higher level of nitrogen caused the higher grain yield, number of kernels per ear, the number of grains per ear row, ear diameter, cob length, grain per plant and plant height. As a result 7.76 ton ha-1 was recorded as high yield while 240 kg ha-1 urea was used, and 5.12 ton ha-1 was recorded as low yield in treatment one with 0 kg ha-1 of nitrogen fertilizer. Finally, as a result using 240 kg ha-1 nitrogen fertilizer is recommended.

scholarly journals Genetic analysis of spike traits in two- and multi-rowed barley crosses

Genetika ◽  
2012 ◽  
Vol 44 (3) ◽  
pp. 475-482
Author(s):  
Milomirka Madic ◽  
Desimir Knezevic ◽  
Aleksandar Paunovic ◽  
Dragan Djurovic
Keyword(s):  
Variance Components ◽  
Genetic Variance ◽  
Grain Weight ◽  
Spike Length ◽  
Grain Number ◽  
Partial Dominance ◽  
Grain Number Per Spike ◽  
Diallel Crossing ◽  
Barley Genotypes ◽  
Mode Of Inheritance

Mode of inheritance and genetic variance components for spike length, grain number per spike and grain weight per spike were evaluated in four parental genotypes and their F1 and F2 hybrids obtained through incomplete diallel crossing. Multi-rowed barley genotypes HVW-247 and Partizan and two-rowed barley genotypes KG-15 and NS-293 were selected for the crossing based on the trait concept with the parents being divergent for spike length, grain number per spike and grain weight per spike. The average values for spike length in F1 and F2 generations were intermediate or close to those of the parent having longer spikes, with the mode of inheritance being partial dominance, dominance or overdominance, depending on the crossing combination. The six-rowed x six-rowed and two-rowed x two-rowed crossing combinations showed dominance of increased grain number per spike and increased grain weight per spike in the inheritance of grain number per spike and grain weight per spike, respectively, whereas the six-rowed x two-rowed cross was predominated by partial dominance.

scholarly journals Morphological Characteristics of Two-rowed Barley (Hordeum sativum ssp. distichum L.) Landraces Originating from Herzegovina

2019 ◽  
Vol 19 (4) ◽  
pp. 287
Author(s):  
Ivan Kovačević ◽  
Đurađ Hajder ◽  
Danijela Kondić ◽  
Dragan Mandić ◽  
Desimir Knežević
Keyword(s):  
Plant Height ◽  
Morphological Characteristics ◽  
Grain Weight ◽  
Spike Length ◽  
Grain Number ◽  
Arithmetic Means ◽  
Significant Treatment ◽  
Barley Landrace ◽  
Grain Number Per Spike ◽  
Significant Difference

Barley is a small grain cereal, tolerant to high temperatures and drought. Due to this characteristic, it can be regarded as a promising crop for production in dry conditions. Research on five spring landraces of two-rowed barley lasted two experimental years (2011 and 2012) in agro-ecological conditions of Banja Luka. In the experiment, the standard cropping practices were applied, without irrigation. The experiment was set as a complete randomized design with four replications. All measurements were performed in 10 plants per replication. Morphological characteristics included plant height (cm), spike length (cm), grain number per spike and grain weight per spike (g). Obtained data were subjected to two-way analysis of variance with landrace and growing season as main factors. Significant treatment or interaction effects were further analysed by Fisher's least significant difference (LSD) test, often utilized for pairwise comparisons among arithmetic means. In all tested traits the maximum average values were obtained in barley landrace AM2, i.e. the plant height (86.89 cm), the spike length (8.90 cm), the grain number per spike (24.74) and the grain weight per spike (1.17 g). Due to these facts, two-rowed barley landrace AM2 can be marked as the most productive in this research, bearing a potential for different crop breeding practices.

Towards improving the drought tolerance of rice in China

2006 ◽  
Vol 4 (1) ◽  
pp. 47-53 ◽  
Author(s):  
Hongyan Liu ◽  
Hanwei Mei ◽  
Xinqiao Yu ◽  
Guihua Zou ◽  
Guolan Liu ◽  
...  
Keyword(s):  
Drought Tolerance ◽  
Recombinant Inbred Lines ◽  
Research Programme ◽  
Complex Trait ◽  
Central China ◽  
High Yield ◽  
Rice Cultivars ◽  
Evaluation Standard ◽  
Qtl Discovery ◽  
Trait Locus

Drought tolerance (DT) is a very complex trait. For the purpose of developing DT rice cultivars, a research programme was initiated in 1997 in China, consisting of four coherent parts: the development of a DT field screen facility and evaluation standard; the collection, evaluation and enhancement of DT rice resources; DT gene/quantitative trait locus (QTL) discovery; and DT rice breeding. More than 2000 rice accessions, mostly from China, were collected and evaluated in a new DT screening facility with a powerful water management system. Eighty-six entries were selected to serve as a core DT collection. A set of 187 recombinant inbred lines was developed for the genetic mapping of DT and high yield-related QTL under drought conditions. Several DT rice cultivars adapted to southern and central China were released. DT rice CMS lines were developed and distributed to most parts of China to encourage the development of DT or water-saving hybrid rice.

scholarly journals Genetic Advance of Durum Wheat Under High Yielding Conditions: The Case of Chile

Agronomy ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 454 ◽  
Author(s):  
Alejandro del Pozo ◽  
Iván Matus ◽  
Kurt Ruf ◽  
Dalma Castillo ◽  
Ana María Méndez-Espinoza ◽  
...  
Keyword(s):  
Durum Wheat ◽  
Grain Quality ◽  
Kernel Weight ◽  
Yield Potential ◽  
High Yield ◽  
Genetic Advance ◽  
Genetic Progress ◽  
Breeding Programs ◽  
Days To Heading ◽  
High Yield Potential

In Chile, durum wheat is cultivated in high-yielding Mediterranean environments, therefore breeding programs have selected cultivars with high yield potential in addition to grain quality. The genetic progress in grain yield (GY) between 1964 and 2010 was 72.8 kg ha−1 per year. GY showed a positive and significant correlation with days to heading, kernels per unit ground area and thousand kernel weight. The gluten and protein content tended to decrease with the year of cultivar release. The correlation between the δ13C of kernels and GY was negative and significant (−0.62, p < 0.05, for all cultivars; and −0.97, p < 0.001, excluding the two oldest cultivars). The yield progress (genetic plus agronomic improvements) of a set of 40–46 advanced lines evaluated between 2006 and 2015 was 569 kg ha−1 per year. Unlike other Mediterranean agro-environments, a longer growing cycle together with taller plants seems to be related to the increase in the GY of Chilean durum wheat during recent decades.

scholarly journals Variability of grain yield components of some new winter wheat genotypes (Triticum aestivum L.)

2011 ◽  
Vol 48 (No. 5) ◽  
pp. 230-235
Author(s):  
M. Sabo ◽  
M. Bede ◽  
Ž.U. Hardi
Keyword(s):  
Winter Wheat ◽  
Grain Yield ◽  
Yield Components ◽  
Vegetation Period ◽  
Grain Number ◽  
Potential Yield ◽  
High Positive Correlation ◽  
Wheat Genotypes ◽  
Grain Number Per Spike ◽  
Grain Yield Components

Variability of grain yield components of some new winter wheat genotypes (e.g. Lara, Lenta, Kruna, Fiesta, Perla, and one line of AG-45) was examined. The analysis of grain yield components of these genotypes and the line was undertaken in a&nbsp;two-year research (1997/1998 and 1998/1999) at two different locations. Significant differences among genotypes, locations and research years were established. In the first experimental year (1997/1998) there was a&nbsp;high positive correlation between nearly all components of the grain yield. The most significant correlation was found between the grain number per spike and grain yield. In the second experimental year (1998/1999) the components did not show statistically significant correlation with the grain yield. It seems that the grain yield of examined genotypes depended significantly on the grain number per spike, grain mass per spike, and agroecological conditions during the vegetation period, whereby the potential yield was determined by the interaction among genotypes, location and production year. The biggest differences among examined genotypes of winter wheat were found in the stem height and spike length.

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