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

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.

2017 ◽  
Vol 53 (No. 3) ◽  
pp. 107-113
Author(s):  
M. Joudi ◽  
A. Ahmadi ◽  
V. Mohammadi

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. 


1978 ◽  
Vol 91 (1) ◽  
pp. 199-205 ◽  
Author(s):  
T. J. Riggs ◽  
E. J. M. Kirby

SummaryMature plant characters and yield components were measured on a two-row (Proctor) and a six-row (Clermont) spring barley variety, the F1 of the cross between them, and the first back-cross to each parent.Whereas shoot dry weight in the F1 significantly exceeded the mid-parental value, and chaff dry weight, stem length and weight per grain showed positive heterosis, grain yield did not exceed the mid-parental value and number of grains per plant showed negative heterosis.A scaling test showed that an additive-dominance model fitted the data in all cases except possibly for dry weight per grain, where the χ2 test approached significance.The partial dominance of the two-row allele (V) for grains set per rachis node exhibited in the mature ears of the F1 was not apparent at anthesis when all the lateral florets were found to have large, apparently normal stamens. However, the ratio of median to lateral grains set over all main shoot ears of the F1 was 1:0·21 with an average of six lateral grains per ear.The results presented indicate that the factors determining total dry-matter production and grain yield are inherited in such a way that the restriction upon grain yield in the F1 is due not to a deficiency of dry matter but to a limited capacity of the plant to store dry matter in the form of grain. This may indicate some developmental interdependence in the expression of yield component characters.


Agriculture ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1077
Author(s):  
Ting Chen ◽  
Yonghe Zhu ◽  
Rui Dong ◽  
Minjian Ren ◽  
Jin He ◽  
...  

The relationship between the sowing patterns and yield performance is a valuable topic for food security. In this study, a novel belt uniform (BU) sowing pattern was reported, and a field experiment with four winter wheat cultivars was carried out over three consecutive growing seasons to compare the dry matter accumulation, harvest index (HI), grain yield and yield components under BU and line and dense (LD) sowing patterns [BU sowing with narrow (15 cm) spacing; BU sowing with wide (20 cm) spacing; LD sowing with wide (33.3 cm) row spacing; LD sowing with narrow (16.6 cm) row spacing]. Four cultivars produced a higher mean grain yield (GY), above-ground biomass (AGB) and spike number (SN) per m2 under the BU sowing patterns than the LD sowing patterns in all three growing seasons. However, yield stability under the BU sowing patterns did not increase with the improved grain yield. The HI did not change with sowing patterns, and the contribution of above-ground biomass to grain yield (84%) was more than 5-fold higher than that of HI (16%). Principal component and correlation analyses indicated that the grain yield was positively correlated with the aboveground biomass and SN, while the HI and 1000-grain weight were not correlated with grain yield. We concluded that (1) the novel BU sowing patterns achieved a higher yield potential in winter wheat but did not further improve yield stability; (2) increasing the dry matter accumulation without changing the HI drove improvements in the SN and grain number per spike, thus increasing grain yield.


1991 ◽  
Vol 18 (1) ◽  
pp. 53 ◽  
Author(s):  
PC Pheloung ◽  
KHM Siddique

Field experiments were conducted in the eastern wheat belt of Western Australia in a dry year with and without irrigation (1987) and in a wet year (1988), comparing three cultivars of wheat differing in height and yield potential. The aim of the study was to determine the contribution of remobilisable stem dry matter to grain dry matter under different water regimes in old and modern wheats. Stem non-structural carbohydrate was labelled with 14C 1 day after anthesis and the activity and weight of this pool and the grain was measured at 2, 18 and 58 days after anthesis. Gutha and Kulin, modern tall and semi-dwarf cultivars respectively, yielded higher than Gamenya, a tall older cultivar in all conditions, but the percentage reduction in yield under water stress was greater for the modern cultivars (41, 34 and 23%). In the grain of Gamenya, the increase in 14C activity after the initial labelling was highest under water stress. Generally, loss of 14C activity from the non-structural stem dry matter was less than the increase in grain activity under water stress but similar to or greater than grain activity increase under well watered conditions. Averaged over environments and cultivars, non-structural dry matter stored in the stem contributed at least 20% of the grain dry matter.


2017 ◽  
Vol 11 ◽  
Author(s):  
Mariateresa Lazzaro ◽  
Ambrogio Costanzo ◽  
Dalia Hosam Farag ◽  
Paolo Bàrberi

Sowing density can have a strong impact on crop stand development during wheat growing cycle. In organic and low-input agriculture, and therefore with minimum or nil use of chemical herbicides, increased sowing density is expected to affect not only grain yield but also weed suppression. In this study we tested, under Mediterranean conditions, six common wheat cultivars (three modern and three heritage) and two three-component mixtures (arranged by combining the three modern or the three heritage cultivars). The different crop stands were tested at sowing densities of 250 (low) and 400 (high, similar to standard sowing density used by local farmers) viable seeds m-2 for two growing seasons. We did not detect a significant effect of crop stand diversity (single cultivars vs mixtures) on grain yield and weed suppression. Differences were ascribed to type of cultivars used (heritage vs modern). Compared to high sowing density, in modern cultivars grain yield did not decrease significantly with low sowing density whereas in heritage cultivars it increased by 15.6%, possibly also because of 21.5% lower plant lodging. Weed biomass increased with low sowing density both in heritage and modern cultivar crop stand types. However, heritage crop stands had, on average, a lower weed biomass (56%) than modern crop stands. Moreover, weed biomass in heritage crop stands at low density (6.82 ± 1.50 g m-2) was lower than that of modern cultivars at the same sowing density (15.54 ± 3.35 g m-2), confirming the higher suppressive potential of the former. We can conclude that lower sowing density can be advisable when using heritage crop stands as it keeps productivity while decreasing plant lodging and maintaining weeds under control.


1989 ◽  
Vol 25 (3) ◽  
pp. 349-355 ◽  
Author(s):  
S. S. Parihar ◽  
R. S. Tripathi

SUMMARYThe response of chickpea to irrigation and phosphorus was studied at Kharagpur in Eastern India. Irrigation scheduling was based on the ratio between irrigation water applied and cumulative pan evaporation (ID/CPE), and had little effect on dry matter accumulation. Increasing the frequency and amount of irrigation reduced the number and dry weight of nodules per plant, which increased to a maximum 70 days after sowing and then declined. Irrigation significantly reduced grain yield as a result of excessive vegetative growth at the expense of pod formation. Application of phosphorus promoted nodulation and increased both nodule dry weight and the concentration of N, P and K in grain and stover. Uptake of N, P and K by the crop was also increased.


2018 ◽  
Vol 64 (No. 7) ◽  
pp. 310-316 ◽  
Author(s):  
Mirosavljevic Milan ◽  
Momcolovic Vojislava ◽  
Maksimovic Ivana ◽  
Putnik-Delic Marina ◽  
Pržulj Novo ◽  
...  

The aim of this study was to improve understanding of (1) the effect of genotypic and environmental factors on pre-anthesis development and leaf appearance traits of barley and wheat; (2) the relationship of these factors with grain yield, and (3) the differences between these two crops across different environments/sowing dates. Therefore, trials with six two-row winter barley and six winter wheat cultivars were carried out in two successive growing seasons on four sowing dates. Our study showed that the observed traits varied between species, cultivars and sowing dates. In both growing seasons, biomass at anthesis and grain yield declined almost linearly by delaying the sowing date. There was no clear advantage in grain yield of wheat over barley under conditions of later sowing dates. Generally, barley produced more leaf and had shorter phyllochron than wheat. Both wheat and barley showed a similar relationship between grain yield and different pre-anthesis traits.


2002 ◽  
Vol 138 (2) ◽  
pp. 153-169 ◽  
Author(s):  
M. J. FOULKES ◽  
R. K. SCOTT ◽  
R. SYLVESTER-BRADLEY

Experiments in three dry years, 1993/94, 1994/95 and 1995/96, on a medium sand at ADAS Gleadthorpe, England, tested responses of six winter wheat cultivars to irrigation of dry-matter growth, partitioning of dry matter to leaf, stem and ear throughout the season, and to grain at final harvest. Cultivars (Haven, Maris Huntsman, Mercia, Rialto, Riband and Soissons) were selected for contrasts in flowering date and stem soluble carbohydrate. Maximum soil moisture deficit (SMD) exceeded 140 mm in all years, with large deficits (>75 mm) from early June in 1994 and from May in 1995 and 1996. The main effects of drought on partitioning of biomass were for a decrease in the proportion of the crop as lamina in the pre-flowering period, and then earlier retranslocation of stem reserves to grains during the first half of grain filling. Restricted water availability decreased grain yield by 1·83 t/ha in 1994 (P<0·05), and with more prolonged droughts, by 3·06 t/ha in 1995 (P<0·001) and by 4·55 t/ha in 1996 (P<0·001). Averaged over the three years, grain yield responses of the six cultivars differed significantly (P<0·05). Rialto and Mercia lost only 2·8 t/ha compared with Riband and Haven which lost 3·5 t/ha. Losses for Soissons and Maris Huntsman were intermediate. In the two years with prolonged drought, the biomass depression was on average greater for Haven (6·0 t/ha) than for Maris Huntsman (4·2 t/ha) (P<0·05). Thus, the grain yield sensitivity of Haven to drought derived, in part, from a sensitivity of biomass growth to drought. Harvest index (HI; ratio of grain to above-ground dry matter at harvest) responses of the six cultivars to irrigation also differed (P<0·05) and contributed to the yield responses. The smallest decrease in HI of the six cultivars with restricted water availability was shown by Rialto (−0·033); this partially explained the drought resistance for this cultivar. The largest decrease was for Maris Huntsman (−0·072). The cultivars differed in flowering dates by up to 9 days but these were poorly correlated with grain yield responses to irrigation. Stem soluble carbohydrate at flowering varied amongst cultivars from 220 to 300 g/m2 in the unirrigated crop; greater accumulation appeared to be associated with better maintenance of HI under drought. It is concluded that high stem-soluble carbohydrate reserves could be used to improve drought resistance in the UK's temperate climate, but that early flowering seems less likely to be useful.


2003 ◽  
Vol 140 (4) ◽  
pp. 395-407 ◽  
Author(s):  
R. E. RUSKE ◽  
M. J. GOODING ◽  
S. A. JONES

Field experiments were conducted over 3 years to assess the effect of a triazole fungicide programme, and additions of strobilurin fungicides to it, on nitrogen uptake, accumulation and partitioning in a range of winter wheat cultivars. Commensurate with delayed senescence, fungicide programmes, particularly when including strobilurins, improved grain yield through improvements in both crop biomass and harvest index, although the relationship with green area duration of the flag leaf (GFLAD) depended on year and in some cases, cultivar. In all years fungicide treatments significantly increased the amount of nitrogen in the above-ground biomass, the amount of nitrogen in the grain and the nitrogen harvest index. All these effects could be linearly related to the fungicide effect on GFLAD. These relationships occasionally interacted with cultivar but there was no evidence that fungicide mode of action affected the relationship between GFLAD and yield of nitrogen in the grain. Fungicide treatments significantly reduced the amount of soil mineral N at harvest and when severe disease had been controlled, the net remobilization of N from the vegetation to the grain after anthesis. Fungicide maintained the filling of grain with both dry matter and nitrogen. The proportionate accumulation of nitrogen in the grain was later than that of dry matter and this difference was greater when fungicide had been applied. Effects of fungicide on grain protein concentration and its relationship with GFLAD were inconsistent over year and cultivar. There were several instances where grain protein concentration was unaffected despite large (1·5 t/ha) increases in grain yield following fungicide use. Dilution of grain protein concentration following fungicide use, when it did occur, was small compared with what would be predicted by adoption of other yield increasing techniques such as the selection of high yielding cultivars (based on currently available cultivars) or by growing wheat in favourable climates.


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