Yield, growth, canopy traits and photosynthesis in high-yielding, synthetic hexaploid-derived wheats cultivars compared with non-synthetic wheats

2017 ◽  
Vol 68 (2) ◽  
pp. 115 ◽  
Author(s):  
Yonglu Tang ◽  
Xiaoli Wu ◽  
Chaosu Li ◽  
Wuyun Yang ◽  
Mingbo Huang ◽  
...  

Continuous improvement of potential yield is one of the most important goals of wheat breeding. The introduction of synthetic hexaploid wheat (SHW) germplasm has broken the bottleneck in potential yield, taking wheat breeding in China’s Sichuan Basin to a new level. However, systematic research on the physiological basis of high-yielding, SHW-derived cultivars has lagged behind. In the present study, three SHW-derived, high-yielding cultivars and three typical, non-synthetic cultivars widely used in wheat production were chosen for a 5-year study. Post-anthesis canopy structure, rates of canopy apparent photosynthesis (CAP), attenuation during grain filling, dry matter partitioning and other physiological parameters were studied. The average yield of the SHW-derived cultivars was 9154 kg ha–1, which was 13.5% higher than that of the non-synthetic cultivars. The increased yield was due to increased biomass and/or increased harvest index (HI). SHW-derived cultivars had shorter but wider flag leaves, with length : width ratio <10. The basal angle and open angle were small at the beginning of anthesis, which gradually increased as grain-filling progressed; the SPAD readings of the flag leaf and penultimate leaf of the SHW-derived cultivars was significantly higher than that of the non-synthetic cultivars from anthesis to mid–late grainfill. The CAP values at anthesis and 20 days post-anthesis were significantly higher in the SHW-derived cultivars than in non-synthetic cultivars, in which the difference was most significant between 10 : 00 and 12 : 00. The dry matter partitioning at anthesis varied significantly among cultivars, and the stem and sheath proportion of the SHW-derived cultivars was larger than that of the non-synthetic cultivars. At maturation, the spike rachis and leaves of the SHW-derived cultivars accounted for significantly smaller proportions of the total aboveground dry weight. Accordingly, the grain proportion was increased by 1–4 percentage points. Yield components were closely related to measured physiological parameters; e.g. grain yield correlated positively with SPAD values (r = 0.960**) and negatively with the proportion of spike rachis at maturation (r = –0.946**). This indicated that a semi-compact plant morphology, with high SPAD readings and high CAP and greater HI, was the physiological basis of high yield in SHW-derived cultivars.

Author(s):  
B. P. Meena ◽  
G. S. Chouhan ◽  
V. K. Meena ◽  
H. S. Sumeriya

Application of eight irrigations (seedling, 6 leaf, knee-high, before tasseling, 50% tasseling, 50% silking, grain formation and grain filling stages) where no stress was occurred significantly increased dry matter distribution. Data related to dry matter partitioning in stem, leaves and cobs at 25, 50, 75 and at harvest stage of crop. In general, irrespective of the treatments, crop attained maximum leaf dry weight at flowering stage. This decreased progressively up to harvest stage. While, stem dry weight showed increasing trend up to tasseling and silking stage and than declined slightly towards harvest stage of the crop. Obviously, cobs dry weight increased linearly from flowering up to harvest stage.


2009 ◽  
Vol 60 (4) ◽  
pp. 316 ◽  
Author(s):  
N. G. Inman-Bamber ◽  
G. D. Bonnett ◽  
M. F. Spillman ◽  
M. L. Hewitt ◽  
Jingsheng Xu

Relatively little is known about the physiological basis for variation in sucrose content among sugarcane clones despite substantial research at the molecular and biochemical levels. We used irrigation and continuous monitoring of photosynthesis and plant extension rate to modify dry matter partitioning in four clones differing widely in sucrose content. Three pot experiments were conducted on two low sucrose content clones, KQ97-2599 and KQ97-2835, and two high sucrose content clones, Q117 and KQ97-5080, in a temperature-controlled glasshouse. As expected, sucrose content on a dry mass basis of whole stalks was greater in high (55% maximum) than in low sucrose clones (40% maximum), but sucrose content in the two clones selected for low sucrose reached 55% in some internodes. Differences between clones in whole-plant net photosynthesis and aerial biomass accumulation were small. However, biomass was distributed over fewer stalks in the high sucrose clones (4–7 stalks per pot) than in the low sucrose clones (9–11 stalks per pot). The high sucrose clones also allocated a considerably greater proportion of dry matter to the stalk (70% maximum) than the low sucrose clones (60% maximum). It is suggested that the relatively large amount of new leaf tissue produced by the high tillering, low sucrose clones placed an additional demand for structural photo-assimilate in these clones and delayed the accumulation of sucrose in the stalk. The results indicated that there is little direct genetic control on the maximum amount of sucrose that can accumulate in stalk tissue and that genetic contrasts in sucrose content reside more in the morphology of the plant and responses to ripening stimuli such as mild water stress, and how these traits influence supply and demand for photo-assimilate.


1988 ◽  
Vol 110 (1) ◽  
pp. 71-79 ◽  
Author(s):  
P. Q. Craufurd ◽  
F. R. Bidinger

SummaryThe phenotype of medium duration pearl millet varieties grown in West Africa differs from that of the shorter duration millets grown in India. African varieties are usually much taller, have longer panicles, fewer productive tillers, and a lower ratio of grain to above-ground dry-matter (harvest index). The effect of crop duration on plant phenotype was investigated in two hybrids using extended daylengths to increase the duration of the vegetative phase (GSl: sowing to panicle initiation). The two hybrids, 841A × J104 and 81A × Souna B, were considered to represent the Indian and African phenotype, respectively. Tiller production and survival, leaf area, and dry-matter accumulation and partition, were monitored over the season. Grain yield and its components were determined at maturity.The two hybrids responded similarly to the short and long daylength treatments. The duration of GSl was increased from 20 to 30 days, resulting in increased number of leaves, leaf area, and stem and total dry-matter accumulation; there was no effect on tiller production and survival, or on panicle growth rate. Grain yield was, therefore, the same in both GSl treatments, and harvest index (HI) was much reduced in the long GSl treatment owing to the increased stem growth. One evident effect of a longer GSl was on dry-matter partitioning between shoots; partitioning to the main stem (MS) was increased, whereas partitioning to the tillers was reduced.There was no difference in crop development, growth or yield between the two hybrids in either GSl treatment. The only significant differences were in the efficiency with which intercepted radiation was converted to dry matter, which was greater in 841A × J104 than in 81A × Souna B, and in the balance between MS and tillers; the grain yield of the MS was significantly greater in 81A x Souna B than in 841A × J104, but at the expense of number of productive tillers.The results demonstrate that both African and Indian phenotypes are equally productive under good agronomic conditions. The lower HI in longer duration African millets is a consequence of a much extended stem growth phase and therefore increased competition between stem and panicle during grain filling. Possible ways to increase grain yield in the medium duration African millets are considered.


Agronomy ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 12
Author(s):  
Witold Grzebisz ◽  
Jarosław Potarzycki

The application of magnesium significantly affects the components of the wheat yield and the dry matter partitioning in the grain-filling period (GFP). This hypothesis was tested in 2013, 2014, and 2015. A two-factorial experiment with three rates of magnesium (0, 25, 50 kg ha−1) and four stages of Mg foliar fertilization (without, BBCH 30, 49/50, two-stage) was carried out. Plant material collected at BBCH: 58, 79, 89 was divided into leaves, stems, ears, chaff, and grain. The wheat yield increased by 0.5 and 0.7 t ha−1 in response to the soil and foliar Mg application. The interaction of both systems gave + 0.9 t ha−1. The Mg application affected the grain yield by increasing grain density (GD), wheat biomass at the onset of wheat flowering, durability of leaves in GFP, and share of remobilized dry matter (REQ) in the grain yield. The current photosynthesis accounted for 66% and the REQ for 34%. The soil-applied Mg increased the REQ share in the grain yield to over 50% in 2014 and 2015. The highest yield is possible, but provided a sufficiently high GD, and a balanced share of both assimilate sources in the grain yield during the maturation phase of wheat growth.


1994 ◽  
Vol 3 (2) ◽  
pp. 195-198 ◽  
Author(s):  
Pirjo Peltonen-Sainio

Duration of vegetative, generative, and grain-filling phases contribute to dry-matter accumulation and partitioning. Fourteen oat (Avena saliva L.) cultivars and six breeding lines were evaluated at the Viikki Experimental Farm, University of Helsinki, in 1988-1990. The following observations were made: (1) a short vegetative period accumulated less dry-matter into vegetative plant organs and resulted in higher grain yield and harvest index (HI), (2) a long period for maximum floret initiation yielded more grains per panicle and high panicle weight and (3) a short grain-filling period yielded high rates of panicle and grain filling associated with high HI. Hence, oat breeding and crop management should aim at improving the synchronization of the growth phases as shown in this study.


2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Adam B. Puteh ◽  
M. Monjurul Alam Mondal ◽  
Mohd. Razi Ismail ◽  
Mohammad Abdul Latif

The experiment was conducted to investigate potential causes of grain sterility in widely cultivated rice variety in Malaysia, MR219 and its two mutant lines (RM311 and RM109) by examining the source-sink relations. RM311 produced increased dry matter yield both at heading and maturity and also showed higher grain yield with greater proportion of grain sterility than the other two genotypes (RM109 and MR219) resulting in the lowest harvest index (49.68%). In contrast, harvest index was greater in RM109 (53.34%) and MR219 (52.76%) with less grain sterility percentage than MR311 indicating that dry matter partitioning to economic yield was better in RM109 and MR219 than in MR311. Results indicated that dry matter allocation per spikelet from heading to maturity was important for reducing grain sterility in rice. The greater above-ground crop dry matter per spikelet was observed in RM109 and MR219 as compared to high dry matter producing genotype; RM311 implies that poor grain filling may not have resulted from dry matter production or source limitation. These findings suggest that grain sterility or poor grain filling in rice is the result of poor translocation and partitioning of assimilates into grains (sink) rather than of limited biomass production or source limitation.


2005 ◽  
Vol 32 (3) ◽  
pp. 189 ◽  
Author(s):  
Fernanda G. González ◽  
Gustavo A. Slafer ◽  
Daniel J. Miralles

Wheat breeding has improved yield potential increasing floret survival through higher dry matter partitioning to the spikes during the stem elongation phase (from terminal spikelet initiation to anthesis). We studied survival of floret primodia in different spikelet positions along the spike in relation to dynamics of spike growth, when dynamics of dry matter partitioning to the spike was altered by photoperiod and shading treatments applied during the stem elongation phase. The cultivar Buck Manantial was exposed to (1) NP+0 un-shaded (natural photoperiod and incoming radiation of the growing season), (2) NP+0 shaded (natural photoperiod but only 33% of the incoming radiation), and (3) NP+6 un-shaded (natural photoperiod extended 6 h and natural incoming radiation). Floret survival increased, depending on spikelet position, 1.1–2.5 fold under un-shaded v. shaded treatments (both under NP+0), and 1.3–1.8 fold under NP+0 v. NP+6 treatments (both un-shaded), without any impact of treatments on the total number of initiated floret primordia. The fate of the floret primordia and its final stage at anthesis were associated with duration of floret development within the stem elongation phase (R2 = 82%, P<0.0001). Florets may be classified into three groups: (i) those that were fertile at anthesis under all treatments (mostly the two florets F1 and F2, proximal to the rachis within the spikelet), (ii) those that reached different stages at anthesis, depending on treatment, and that contributed differentially to the number of fertile florets at anthesis (mostly the florets F3, F4 and F5, positioned in the middle of the spikelet), and (iii) those that did not contribute to the number of fertile florets under any treatment (mostly the florets ≥ F6). Degeneration of florets in group (ii) was associated with spike growth at maximum rate, explaining the strong relationship observed between spike dry weight at anthesis and number of fertile florets. However, degeneration of florets in group (iii) seemed to occur before spike growth at maximum rate. Survival of florets positioned in the middle of the spikelets could be improved by increasing spike growth through manipulation of photoperiod sensitivity during stem elongation.


Sign in / Sign up

Export Citation Format

Share Document