scholarly journals Changes in stem and spike related traits resulting from breeding in Iranian wheat cultivars: associations with grain yield

2017 ◽  
Vol 53 (No. 3) ◽  
pp. 107-113
Author(s):  
M. Joudi ◽  
A. Ahmadi ◽  
V. Mohammadi
Keyword(s):  
Grain Yield ◽  
Selection Criterion ◽  
Dry Weight ◽  
Grain Filling ◽  
Specific Weight ◽  
Indirect Selection ◽  
Wheat Cultivars ◽  
Terminal Drought ◽  
Positive Correlations ◽  
Terminal Drought Stress

This study investigated changes in stem and spike characteristics resulting from breeding in Iranian wheat cultivars, and their relationship with grain yield. Eighty-one wheat cultivars released between 1930 and 2006 were examined under well-watered (WW) and terminal drought stress (DS) conditions in Karaj during 2007–2008 and 2008–2009 and under WW condition at Parsabad in Moghan region during 2010–2011. A genetic improvement over time in stem specific weight (SSW) along with significant positive correlations between this trait and grain yield were found at Karaj under DS conditions and at Parsabad, suggesting that SSW could be used as an indirect selection criterion for yield in these environments. Time-dependent changes in spike dry weight showed that the magnitude of partitioned photoassimilates to the spike during the phase anthesis – 16 days after anthesis (16 DAA) was not changed by breeding. However, during the 16 DAA ‒ maturity phase, modern cultivars had more photoassimilates allocated to the spike than the old ones. This suggests that the sink is more limited during early grain growth than during the end of grain filling. 

scholarly journals Genotypic variation in pre- and post-anthesis dry matter remobilization in Iranian wheat cultivars: associations with stem characters and grain yield

2018 ◽  
Vol 54 (No. 3) ◽  
pp. 123-134
Author(s):  
Joudi Mehdi ◽  
Ende Wim Van Den
Keyword(s):  
Grain Yield ◽  
Dry Matter ◽  
Genotypic Variation ◽  
Dry Weight ◽  
Specific Weight ◽  
Stem Length ◽  
Wheat Cultivars ◽  
Growing Seasons ◽  
Sink Demand ◽  
The Given

The amount of carbohydrate accumulation and remobilization in the wheat stem can be estimated by monitoring changes in stem dry matter. Eighty-one wheat cultivars were examined in the Moghan region of Iran during the 2010–2011 and 2013–2014 growing seasons. Pre- and post-anthesis dry matter remobilization was quantified in the tested cultivars and their associations with stem characteristics and grain yield were investigated. There was substantial variation in stem length, weight, and specific weight among the tested cultivars. The majority of the cultivars did not show pre-anthesis dry matter remobilization in the stem or internodes. In contrast, most of them used stem dry matter that had been stored after anthesis, suggesting that under the given conditions, current photosynthesis along with post-anthesis dry matter remobilization could meet most of the sink demand. Generally, there were no significant associations between stem length and dry matter remobilization (r = –0.05 to 0.03; P ≥ 0.05). Stem weight (r = 0.42 to 0.65; P ≤ 0.01) and specific stem weight (r = 0.44 to 0.60; P ≤ 0.01) measured at 16 days after anthesis correlated positively and significantly with dry weight loss from the stem. Intriguingly, no clear relationships were found between dry matter remobilization and grain yield (r = –0.13 to 0.04; P ≥ 0.05), suggesting that there are no simple relationships between these traits. The association between dry matter remobilization and grain yield may be different depending on the examined cultivars.

scholarly journals Stem carbohydrate dynamics during post anthesis period in diverse wheat genotypes under different environments

2019 ◽  
Vol 6 (sp1) ◽  
pp. 556-559
Author(s):  
Vidisha Thakur ◽  
Girish Chandra Pandey ◽  
Jagadish Rane
Keyword(s):  
Genetic Variation ◽  
Grain Yield ◽  
Grain Filling ◽  
Water Soluble ◽  
Soluble Carbohydrates ◽  
Growth Stages ◽  
Terminal Drought ◽  
Grain Filling Period ◽  
Terminal Drought Stress ◽  
Carbohydrate Dynamics

The contribution of stem water soluble carbohydrates (SWSCs) to grain biomass of wheat ranges from 10 to 20% under irrigated condition and 40 to 60% under stresses such as terminal heat and drought. Genetic variation in SWSC and its mobilization can be useful to increase the grain yield of wheat under harsh environments. Hence, a set of 16 genotypes varying in spike morphology and grain yield was grown in field under timely sown, late sown and terminal drought stress conditions. The anthrone method was used to measure the SWSC concentration in the dried peduncle and penultimate internodes in three replicates at 3 growth stages starting from anthesis. The effect of delay in sowing and terminal drought on the SWSC concentration was significant from anthesis to 14 days after anthesis. Significant genetic variation was observed in the rate of post anthesis change in SWSC during the early grain filling period under the three conditions which partially contributed to the variation in grain yield per spike among the genotypes. Due to sterile florets and/or shorter grain filling duration, all the genotypes did not have a correlation between grain weight per spike and rate of decrease of SWSCs. Thus, our experiments reconfirm the significance of SWSC in present cultivars of wheat and also the scope for exploiting the genetic variation in this trait.

Variation in harvest index of modern spring barley, oat and wheat cultivars adapted to northern growing conditions

2007 ◽  
Vol 146 (1) ◽  
pp. 35-47 ◽  
Author(s):  
P. PELTONEN-SAINIO ◽  
S. MUURINEN ◽  
A. RAJALA ◽  
L. JAUHIAINEN
Keyword(s):  
Grain Yield ◽  
Harvest Index ◽  
Stand Structure ◽  
Spring Barley ◽  
Principal Component ◽  
Grain Filling ◽  
Wheat Cultivars ◽  
Cereal Species ◽  
Growing Conditions ◽  
Cereal Cultivars

SUMMARYIncreased harvest index (HI) has been one of the principal factors contributing to genetic yield improvements in spring barley (Hordeum vulgare L.), oat (Avena sativa L.) and wheat (Triticum aestivum L.) cultivars. Although high HI demonstrates high-yielding ability when cultivars are compared, it can also indicate challenges to yield formation when comparisons are made across differing growing conditions. The present study was designed to investigate variation in HI among modern cereal cultivars relative to that brought about by a northern environment, to assess whether HI still explains the majority of the differences in grain yield when only modern cereal cultivars are compared, and to monitor key traits contributing to HI. Stability of HI was also investigated with reference to the role of tillers. Twelve experiments (3 years, two locations, two nitrogen fertilizer regimes) were carried out in southern Finland to evaluate 12 two-row spring barley, 10 six-row barley, 10 oat and 11 wheat cultivars. In addition to HI, days to heading and maturity, length of grain filling period, grain yield, test weight and 13 traits characterizing plant stand structure were measured and analysed with principal component analysis (PCA) to detect traits associated with HI and those contributing to stability of HI. Although only modern cereals were studied, differences among cultivars were significant both in mean HI and stability of HI, and HI was associated with short plant stature in all modern cereal species. Also, single grain weight was associated with HI in all species. Differences between, but not within, species in HI were partly attributable to differences in tiller performance. Grain yield was associated closely with HI except in two-row barley. It may be possible to further increase HI of wheat, as it still was relatively low. High HI did, however, not indicate the degree of success in yield determination when environments are compared.

Characteristics of the canopy, root system and grain yield of a crop of Lupinus angustifolius cv. Unicrop

1975 ◽  
Vol 26 (3) ◽  
pp. 497 ◽  
Author(s):  
EAN Greenwood ◽  
P Farrington ◽  
JD Beresford
Keyword(s):  
Carbon Dioxide ◽  
Grain Yield ◽  
Leaf Area ◽  
Time Course ◽  
Dry Weight ◽  
Grain Filling ◽  
Main Axis ◽  
Carbon Dioxide Exchange ◽  
Area Index ◽  
Plant Parts

The time course of development of a lupin crop was studied at Bakers Hill, Western Australia. The aim was to gain insight into the crop factors influencing yield. Weekly measurements were made of numbers and weights of plant parts, and profiles of roots, leaf area and light interception. A profile of carbon dioxide in the crop atmosphere was taken at the time of maximum leaf area, and the net carbon dioxide exchange (NCE) of pods was estimated for three successive weeks. The crop took 10 weeks to attain a leaf area index (LAI) of 1 and a further 9 weeks to reach a maximum LAI of 3.75, at which time only 33% of daylight reached the pods on the main axis. Once the maximum LAI was attained at week 19, leaf fall accelerated and rapid grain filling commenced almost simultaneously on all of the three orders of axes which had formed pods. Measurements of NCE between pods on the main axis and the air suggest that the assimilation of external carbon dioxide by the pods contributed little to grain filling. Grain dry weight was 2100 kg ha-1 of which 30%, 60% and 10% came from the main axis, first and second order apical axes respectively. Only 23% of the flowers set pods and this constitutes an important physiological limitation to grain yield.

scholarly journals Grain filling parameters in high-yielding ns wheat cultivars

2008 ◽  
pp. 53-58
Author(s):  
Milka Brdar ◽  
Marija Kraljevic-Balalic ◽  
Borislav Kobiljski
Keyword(s):  
Multivariate Analysis ◽  
Nonlinear Regression ◽  
Environmental Conditions ◽  
Dry Weight ◽  
Grain Filling ◽  
Grain Weight ◽  
Cultivar Differences ◽  
Wheat Cultivars ◽  
Estimated Parameters ◽  
Grain Filling Duration

Grain yield of wheat is dependent on grain weight, which is the result of grain filling duration and rate. The study was undertaken to examine the relation between grain weight and rate and duration of grain filling in five high-yielding NS wheat cultivars. Stepwise multivariate analysis of nonlinear regression estimated grain filling parameters was used to examine cultivar differences in grain filling. On the basis of three-year average, the highest grain dry weight had cultivar Renesansa, and the lightest grains were measured for cultivar Evropa 90. Stepwise multivariate analysis indicated that all three nonlinear regression estimated parameters (grain weight, rate and duration of grain filling) were equally important in characterizing the grain filling curves of the cultivars studied, although sequence of their significance varied in different years, which is probably caused by different environmental conditions in three years of experiment.

scholarly journals Effects of Enzymatic Biofertiliser on Growth and Yield of Lentil Genotypes under Deficit Irrigation/ Enzimatisko Biomçslojumu Ietekme Uz Daþâdu Lçcu Genotipu Augðanu Un Raþu Irigâcijas Trûkuma Apstâkïos

2014 ◽  
Vol 68 (3-4) ◽  
pp. 174-179
Author(s):  
Mohsen Janmohammadi ◽  
Hamid Mostafavi ◽  
Naser Sabaghnia
Keyword(s):  
Drought Stress ◽  
Grain Yield ◽  
Deficit Irrigation ◽  
Morphological Traits ◽  
Foliar Application ◽  
Growth And Yield ◽  
Sowing Time ◽  
Ecological Zones ◽  
Terminal Drought ◽  
Terminal Drought Stress

Abstract Lentil (Lens culinaris Medic.) is one of the important pulse crops in semiarid agro-ecological zones with a Mediterranean-type climate. Terminal drought stress and poor plant nutrition are important factors limiting crop under these regions. The effects of enzymatic biofertiliser (MOG) application at sowing time or during reproductive stage on some morphological traits and yield components of eight lentil lines were evaluated under deficit-irrigation conditions at Maragheh (37°23' N; 46°16' E) in northwestern Iran. Results revealed that application of biofertiliser did not significantly affect most of the morphological traits. However, foliar application of MOG during early flowering stage somewhat increased 100-grain weight and grain yield and decreased the number of empty pod per plant. Moreover, the results indicated that there was significant diversity between lentil lines for the investigated traits. The best performance for grain yield was recorded for FLIP 86-35L. The overall lack of considerable response of lentil to the MOG treatments may suggest that the optimal efficiency of biofertiliser cannot be achieved under water scarcity conditions. Improvement in the adaptation of enzymatic fertilisers to semi arid regions with terminal drought stress requires to be increased.

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 Evidence for genotypic differences among elite lines of common bean in the ability to remobilize photosynthate to increase yield under drought

2016 ◽  
Vol 155 (6) ◽  
pp. 857-875 ◽  
Author(s):  
I. M. RAO ◽  
S. E. BEEBE ◽  
J. POLANIA ◽  
M. GRAJALES ◽  
C. CAJIAO ◽  
...  
Keyword(s):  
Drought Stress ◽  
Grain Yield ◽  
Common Bean ◽  
Harvest Index ◽  
Genotypic Differences ◽  
Area Index ◽  
Wild Bean ◽  
Terminal Drought ◽  
Terminal Drought Stress ◽  
Pod Harvest Index

SUMMARYCommon bean (Phaseolus vulgaris L.) is the most important food legume for human consumption. Drought stress is the major abiotic stress limitation of bean yields in smallholder farming systems worldwide. The current work aimed to determine the role of enhanced photosynthate mobilization to improve adaptation to intermittent and terminal drought stress and to identify a few key adaptive traits that can be used for developing drought-resistant genotypes. Field studies were conducted over three seasons at Centro Internacional de Agricultura Tropical, Palmira, Colombia to determine genotypic differences in adaptation to intermittent (two seasons) and terminal (one season) drought stress compared with irrigated conditions. A set of 36 genotypes, including 33 common bean, two wild bean and one cowpea were evaluated using a 6 × 6 lattice design under irrigated and rainfed field conditions. Three common bean elite lines (NCB 226, SEN 56, SER 125) were identified with superior levels of adaptation to both intermittent and terminal drought stress conditions. The greater performance of these lines under drought stress was associated with their ability to remobilize photosynthate to increase grain yield based on higher values of harvest index, pod harvest index, leaf area index and canopy biomass. Two wild bean germplasm accessions (G 19902, G 24390) showed very poor adaptation to both types of drought stress. One small-seeded black line (NCB 226) was superior in combining greater values of canopy biomass with greater ability to mobilize photosynthates to grain under both types of drought stress. Two small-seeded red lines (SER 78, SER 125) seem to combine the desirable traits of enhanced mobilization of photosynthates to seed with effective use of water through canopy cooling under terminal drought stress. Pod harvest index showed significant positive association with grain yield under both types of drought stress and this trait can be used by breeders as an additional selection method to grain yield in evaluation of breeding populations for both types of drought stress.

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