Crop growth model‐enabled genetic mapping of biomass accumulation dynamics in photoperiod‐sensitive sorghum

Biomass sorghums [Sorghum bicolor (L.) Moench] are short-day photoperiod sensitive (PS) types, meaning that the crop will grow vegetatively late into the fall season in subtropical and temperate environments. This feature results in high biomass yield potential and mitigates drought susceptibility. The objective of this study is to assess biomass growth patterns and associated changes in composition over a growing season for PS sorghum. The experiment had a split-plot design with two replications, six PS sorghum genotypes, and 13 harvest dates. Harvest started at 60 days after planting (DAP) and continued every 15 days thereafter in both College Station (CS) and Corpus Christi (CC) in Texas, 2010. At each harvest, dry biomass yield, plant height and biomass composition (percent lignin and cellulose) were measured. For all genotypes, biomass accumulation followed a standard growth pattern which included an early lag phase, followed by a log phase of growth and finally, a general reduction in the rate of accumulation. The early lag phase ended at approximately 70 DAP, the log phase of growth ended at approximately 125 DAP, and biomass yields maximized between 180 and 225 DAP. The highest yielding genotype produced 24 Mg ha−1. Plant heights up to 400 cm were also measured between 180 and 225 DAP. Plant height and biomass yield patterns were similar, indicating that height is important to increase yield. Lignin and cellulose concentrations increased with time; at the highest yields (between 180 and 225 DAP), maximum lignin content were 14.5 to 15.5 % and maximum cellulose content was 31 to 32 %. As with yield potential, significant differences were detected for composition as well. The growth curves indicate that PS biomass sorghum yields sufficiently and can be harvested as early as 130 DAP with maximum sorghum biomass accumulation occurring between 180 and 225 days. Thus, with careful selection and deployment of biomass sorghum hybrids, the harvest season of biomass sorghum can be extended over a 3-month period in southern regions of the US

Growth dynamics of determinate soybean in narrow and wide rows at late planting dates

Purpose: To evaluate the potential of Lonicera macranthoides Hand. -Mazz. Yulei1 suspension culture system for enhanced production of the main secondary metabolite, chlorogenic acid.Methods: The callus of L. macranthoides Hand.-Mazz. “Yulei1” was suspension cultured in B5 liquid medium supplemented with different plant growth regulators. Biomass accumulation was calculated by weight method and chlorogenic acid production was measured using high performance liquid chromatography (HPLC). HPLC was carried out on C18 analytical column at 35 °C and the detection wavelength was set at 324 nm.Results: The results showed that maximum accumulation of biomass and chlorogenic acid were achieved 15 days after culture growth. The optimized conditions for biomass accumulation and chlorogenic acid production were 50 g/L of inoculum on fresh weight basis, B5 medium supplemented with plant growth regulators, 30 - 40 g/L sucrose and initial medium pH of 5.5. Maximum accumulation of chlorogenic acid and biomass were observed when the culture medium was supplemented with 2.0 mg/L6-BA. Optimal accumulation of chlorogenic acid was observed using combination of hormones 2.0 mg/L 6-Benzyladenine (BA) + 0.5 mg/L2, 4-Dichlorophenoxyacetic acid (2,4-D), while optimal accumulation of biomass was observed with 2.0 mg/L 6-BA + 2.0 mg/L2, 4-D. In addition, phenylalanine also contributed to the synthesis of chlorogenic acid at a concentration > 50 mg/L.Conclusion: Cell suspension cultures of L. macranthoides Hand.-Mazz. “Yulei1” have successfully been established. The findings provide a potential basis for large scale production of chlorogenic acid using cell suspension cultures of L. macranthoides.Keywords: Lonicera macranthoides, Cell suspension culture, Chlorogenic acid, Phenylalanine, Optimization

The effects of different NaCl concentrations, nitrogen sources, carbon sources, and carbon to nitrogen molar ratios on biomass accumulation and polyhydroxybutyrate (PHB) production were studied in batch cultures of the marine photosynthetic bacterium Rhodovulum sulfidophilum P5 under aerobic-dark conditions. The results show that the accumulation of PHB in strain P5 is a growth-associated process. Strain P5 had maximum biomass and PHB accumulation at 2%–3% NaCl, suggesting that the bacterium can maintain growth and potentially produce PHB at natural seawater salinity. In the nitrogen source test, the maximum biomass accumulation (8.10±0.09 g/L) and PHB production (1.11±0.13 g/L and 14.62%±2.2 of the cell dry weight) were observed when peptone and ammonium chloride were used as the sole nitrogen source. NH4+-N was better for PHB production than other nitrogen sources. In the carbon source test, the maximum biomass concentration (7.65±0.05 g/L) was obtained with malic acid as the sole carbon source, whereas the maximum yield of PHB (5.03±0.18 g/L and 66.93%±1.69% of the cell dry weight) was obtained with sodium pyruvate as the sole carbon source. In the carbon to nitrogen ratios test, sodium pyruvate and ammonium chloride were selected as the carbon and nitrogen sources, respectively. The best carbon to nitrogen molar ratio for biomass accumulation (8.77±0.58 g/L) and PHB production (6.07±0.25 g/L and 69.25%±2.05% of the cell dry weight) was 25. The results provide valuable data on the production of PHB by R. sulfidophilum P5 and further studies are on-going for best cell growth and PHB yield.

了解林木功能性状在不同培育模式下的变异和关联，对揭示林木生态适应性及其生态功能具有重要意义。选取了亚热带地区两种常见人工林树种杉木、大叶榉幼苗为研究对象，设置4种不同栽培模式的盆栽试验：单一杉木（4C），单一大叶榉（4Z）和杉木、大榉树3种混栽模式（1C3Z、2C2Z、3C1Z），研究不同混交比例对其叶、茎、根功能性状的影响。结果表明：（1）杉木总叶面积、叶干物质含量、净光合速率、蒸腾速率和气孔导度在混栽模式下显著减小，而比叶面积显著增大；根长和比根长在不同处理间无显著差异；叶、茎、根生物量和单株总生物量在混栽模式下显著低于4C处理，不同混栽模式之间差异不显著。（2）大叶榉单叶面积在3C1Z处理下最高，总叶面积随大叶榉在树种组成中所占比例的降低而逐渐增大，比叶面积在不同处理间无显著差异，叶干物质含量、净光合速率、蒸腾速率和气孔导度均在2C2Z处理下最大，而瞬时水分利用效率在2C2Z处理下最小；根长在3C1Z处理下显著增大，比根长在不同处理间无显著差异；叶、茎、根生物量和单株总生物量随大叶榉在树种组成中所占比例的降低而逐渐增大。综合来看，杉木和大叶榉混合处理中杉木种间竞争大于种内竞争，而大叶榉相反；随杉木在混栽处理中比例减少，其主要通过增加比叶面积，提高净光合速率，减少茎生物量积累来适应种间竞争关系；而大叶榉随其在混栽处理中比例的减少，显著增加叶面积和根长来提高资源利用率，减少地下资源分配，提高地上茎生物量积累。因此，树种混交比例将显著影响林木功能性状及其生物量积累，选择适宜混交比例对混交林可持续经营具有重要意义。;Understanding the variation and correlation of plant functional traits among different planting patterns is of great importance to reveal the ecological adaptability and function of different tree species. The variations of functional traits in two common tree species' seedlings (Cunninghamia lanceolata and Zelkova schneideriana) in subtropical area were studied among different mixing proportions based on pot experiment. These mixing proportions included a single-species C. lanceolata planting pattern (4C), a single-species Z. schneideriana planting pattern (4Z) and three mixed treatments (1C3Z, 2C2Z, and 3C1Z). The results showed that:(1) total leaf area, leaf dry matter content, net photosynthetic rate, transpiration rate and stomatal conductance of C. lanceolata decreased significantly in the mixed treatments compared to 4C treatment, while specific leaf area increased significantly. Root length and specific root length were no difference among different treatments. Leaf biomass, stem biomass, root biomass and total biomass per plant of C. lanceolata among different treatments were significantly lower than in the 4C treatment, and these variables were no significant difference among mixed treatments. (2) mean leaf area of Z. schneideriana was the highest in the 3C1Z treatment. Total leaf area increased gradually with the decrease of the proportion of Z. schneideriana in tree species composition, specific leaf area was no significant difference among treatments, leaf dry matter content was the highest in the 2C2Z treatment. Net photosynthetic rate, transpiration rate and stomatal conductance of Z. schneideriana were the highest in the 2C2Z treatment, while the instantaneous water use efficiency was the lowest in the 2C2Z treatment. Root length of Z. schneideriana increased significantly in the 3C1Z treatment, while specific root length showed less variation among different treatments. Leaf biomass, stem biomass, root biomass and total biomass per plant of Z. schneideriana increased gradually with the decrease of the proportion of Z. schneideriana in tree species composition. Overall, interspecific competition was greater than intraspecific competition for C. lanceolata in mixed C. lanceolata and Z.schneideriana treatments, while the pattern was opposite for Z. schneideriana. With the decrease of the proportion of C. lanceolata in mixed treatments, C. lanceolata enhanced interspecific competition by increasing specific leaf area and net photosynthetic rate and reducing stem biomass accumulation. While with the decrease of the proportion of Z. schneideriana in mixed treatments, Z. schneideriana significantly increased leaf area and root length to improve resource utilization, and reduced underground resource allocation and increased aboveground stem biomass accumulation. Therefore, mixing proportion of tree species will significantly affect functional traits and biomass accumulation. Determining appropriate mixing proportion is of great significance for sustainable management of mixed-plantation.

Evaluation of a Dynamic Simulation Model for Tomato Crop Growth and Development

According to prevalent agronomic practices for cultivation of Brassica genotypes, N is applied in split doses, while S is applied as a basal dose. This may create imbalance in the supply of these nutrients during the growth and development of the crop because metabolism of N and that of S are closely linked and play a central role in protein synthesis. The requirement of one depends on the supply of the other, and the imbalance in their supply causes a reduction in the yield because of reduced uptake and assimilation of the two nutrients. In the present investigation, therefore, S was applied in split doses, along with N, to study its effect on growth and yield attributes of Brassica juncea (L.) Czern. and Coss. (V1) and Brassica campestris L. (V2). In the experiment, conducted in the field, 40 kg S ha−1 as CaSO4 (gypsum) was applied either in a single basal application (S1) or in two (S2) or three (S3) split applications; and 100 kg N ha−1 as urea was applied either in two (N2) or three (N3) splits. Biomass accumulation, leaf-area index (LAI), leaf-area duration (LAD), crop growth rate (CGR) and photosynthesis in the leaves were determined at various phenological stages. Split application of S and N (S2N2 or S3N3) resulted in significant improvement in growth and yield of both the genotypes compared with the application of S in a single basal application and N in two splits (S1N2). Genetic variability was observed between the two genotypes in response to split application of S and N. V1 responded better when S and N was applied in two split doses (S2N2) than when it was applied as S1N2 or S3N3 This S2N2 treatment resulted in 40.0, 39.7, 35.5, 48.2 and 18.1% enhancement in biomass accumulation, LAI, LAD, CGR and photosynthetic rate, respectively in comparison with S1N2. Seed yield, biological yield and harvest index were improved by 38.3, 26.3 and 9.5%, respectively, by S2N2 over the results obtained with S1N2. In the case of V2, three split applications of S and N (S3N3) resulted in maximum growth and yield. Increases in biomass accumulation, LAI, LAD, CGR and photosynthetic rate due to application of S3N3 were 48.4, 81.3, 77.9, 101.1 and 28.6% respectively, over the results of S1N2. Seed yield, biological yield and harvest index improved by 41.3, 26.9 and 11.6% respectively, with this treatment.On the basis of results obtained in this study, it can be concluded that S must be applied in split doses for optimum growth and yield of Brassica genotypes. The variability in response of these genotypes to split application of S and N was due to differences in flowering time, as V1 flowered earlier (just after the application of the second dose of S and N) than V1 (just after the application of the third dose of S and N). Key words: Brassica genotypes, nitrogen, sulphur, split application, growth, yield

Under the rice–wheat cropping system (RWS), the continuous cropping of rice (Oryza sativa L.) and wheat (Triticum aestivum L.) deplete soil fertility, and reduce crop growth and total rice biomass. In RWS, both phosphorus (P) and zinc (Zn) deficiencies are considered important nutritional constraints for reducing rice crop growth rates (CGR) and total biomass/biological yield (BY). The objective of this experiment was to investigate the impact of phosphorus (0, 40, 80, 120 kg P ha−1) and zinc rates (0, 5, 10, 15 kg Zn ha−1) on CGR and BY of three rice genotypes [fine (Bamati-385) versus coarse (Fakhre-e-Malakand and Pukhraj)] in Northwestern Pakistan during summer 2011 (Y1) and 2012 (Y2). The results revealed that higher CGR at various growth stages and total BY was obtained with the integrated use of higher phosphorus (80 and 120 kg P ha−1) and zinc rates (10 and 15 kg Zn ha−1). The lower CGR and BY were recorded when P and Zn were not applied (control) or when P and Zn were applied alone. In the case of rice genotypes, the highest CGR and BY were recorded for the hybrid rice (Pukhraj) than the other two genotypes. The CGR was increased to the highest level at the heading stage as compared to tillering and physiological maturity. The increase in CGR had a positive impact on the total BY of rice cultivars. The increase in BY had a positive relationship with grain yield and grower’s income. It was concluded from the study that the combined application of higher P and Zn rates to the coarse rice genotypes (Fakhre-e-Malakand and Pukhraj) could increase CGR, total BY, crop productivity and profitability.

Tropical wheat response to irrigation and nitrogen in a Sahelian environment. II. Biomass accumulation, nitrogen uptake and water extraction

Sugar accumulation in sorghum (Sorghum bicolor (L.) Moench) stems is a complex trait that is particularly plastic in response to photoperiod. This study investigated sucrose accumulation in a sterile (no grain filling) and fertile near-isogenic line of the photoperiod-sensitive cultivar IS2848 in two greenhouse experiments. Variable phenology was induced by applying a short (12-h PP) and a long (13-h PP) photoperiod. Dynamics of plant growth, phenology, sugar accumulation and related enzyme activities in internodes were investigated. Under 13-h PP, plants flowered 28 days later and attained threefold higher sucrose concentration at anthesis compared with those under 12-h PP. Sucrose accumulation in individual internodes was driven by organ physiological age, not by plant phenology. Competition with grain filling was marginal but greater under 12-h PP (i.e. when sucrose accumulation in internodes occurred after flowering). Enzyme activities showed marked developmental patterns but contributed little to explaining differences between treatments and genotypes. The study demonstrates that sucrose storage physiology in sweet sorghum resembles that of sugarcane (Saccharum spp.) but is more complex due to photoperiod effects on phenology. It confirms the field results on 14 sorghum genotypes contrasting for phenology and photoperiod sensitivity presented in a companion paper. Perspectives for developing sorghum ideotype concepts for food and fuel crops are discussed.

Grain yield in wheat: Effects of radiation during spike growth period

Sorghum (Sorghum bicolor L. Moench) has high water use efficiency, and is therefore widely cultivated in the Southern High Plains (SHP). Interest in sorghums for biofuel feedstock has increased recently as ethanol demand expands. Unlike grain sorghum, little data are available on N fertilizer requirements for ethanol production from sweet or forage sorghum production. Our objective was to compare ethanol yields and determine optimal N fertilizer needs for ethanol production from sweet sorghum and photoperiod sensitive (PPS) sorghum with limited irrigation in the SHP. Nitrogen fertilizer rates from 0 to 168 N kg ha−1 were tested on four sorghum cultivars (two sweet and two PPS) on Acuff sandy clay loam near Lubbock, TX in 2008 and 2009. Total dry matter (TDM) yields averaged 13 Mg ha−1 across years, cultivars, and N rates. Nitrogen fertilizer response in TDM was observed only in 2009, but bagasse yields responded to N fertilizer in both years. Cellulosic ethanol yields were greater with PPS sorghums than with sweet sorghums in both years. However, total ethanol yields were greater with sweet sorghums than PPS sorghums. Cellulosic ethanol and total ethanol yields responded to N in 2009 only. High preplant soil NO3 in 2008 apparently precluded TDM and ethanol yield response to N fertilizer. The optimum agronomic N fertilizer rate for ethanol and TDM across all four sorghums was 108 kg ha−1 respectively in 2009. The optimum N fertilizer rate for maximum profit with $ 0.70 kg N−1 and $.50 L−1 ethanol was 101 kg ha−1

The rate of N uptake of crops is highly variable during crop development and between years and sites. However, under ample soil N availability, crop N accumulation is highly related to crop growth rate and to biomass accumulation. Critical N concentration has been defined as the minimum N concentration which allows maximum growth rate. Critical N concentration declines during crop growth. The relationship between critical N concentration and biomass accumulation over the growth period of a crop is broadly similar within major C(3) and C(4) cultivated species. Therefore, the critical N concentration concept is widely used in agronomy as the basis of the diagnosis of crop N status, and allows discrimination between situations of sub-optimal and supra-optimal N supply. The relationship between N and biomass accumulation in crops, relies on the interregulation of multiple crop physiological processes. Among these processes, N uptake, crop C assimilation and thus growth rate, and C and N allocation between organs and between plants, play a particular role. Under sub-optimal N supply, N uptake of the crop depends on soil mineral N availability and distribution, and on root distribution. Under ample N supply, N uptake largely depends on growth rate via internal plant regulation. Carbon assimilation of the crop is related to crop N through the distribution of N between mature leaves with consequences for leaf and canopy photosynthesis. However, although less commonly emphasized, carbon assimilation of the crop also depends on crop N through leaf area development. Therefore, crop growth rate fundamentally relies on the balance of N allocation between growing and mature leaves. Nitrogen uptake and distribution also depends on C allocation between organs and N composition of these organs. Within shoots, allocation of C to stems generally increases in relation to C allocation to the leaves over the crop growth period. Allocation of C and N between shoots and roots also changes to a large extent in relation to soil N and/or crop N. These alterations in C and N allocation between plant organs have implications, together with soil availability and carbon assimilation, on N uptake and distribution in crops. Therefore, N uptake and distribution in plants and crops involves many aspects of growth and development. Regulation of nitrogen assimilation needs to be considered in the context of these interregulatory processes.

Variability in the yield of extra‐short‐duration (ESD) pigeonpea [Cajanus cajan (L.) Huth.] genotypes in drought environments is related to variation in crop growth rate (CGR) and total dry matter (TDM) production. Our investigation was aimed at assessing the importance of canopy attributes in determining the growth of ESD pigeonpea under contrasting moisture regimes. Using two automated rain‐out shelters (ROS), six genotypes were grown under well watered conditions or with water deficit imposed from flowering until maturity. Water deficit significantly decreased the cumulative intercepted photosynthetically active radiation (CIR). The relationship between biomass accumulation and CIR was linear and water deficit affected the slope of the relationship (i.e., radiation use efficiency, RUE) (b = 1.92 g MJ−1 for well watered vs. 1.43 g MJ−1 for water deficit). Genotypes differed in RUE under well watered (1.70 to 2.19 g MJ−1) and moisture deficit (1.30 to 1.66 g MJ−1) conditions. Genotypic variation in canopy attributes was significant. Leaf area duration (LAD) significantly correlated with CGR only under well watered conditions. Cumulative intercepted radiation and RUE accounted for nearly 99% of the genotypic variation in CGR under both moisture regimes, of which RUE alone contributed nearly 90%. Variation among genotypes in CIR alone did not explain the differences in dry matter accumulation under either moisture regime. Only RUE explained more than 90% of the genotypic variation in CGR and 70% in TDM under both moisture regimes. The results indicated that RUE is critical in determining pigeonpea productivity under well watered and moisture‐deficit regimes.

Background: Rice is most important staple meal for more than half of the world’s population. The conventional method of rice production uses a lot of water, requires a lot of labor and has a negative impact on soil and environmental health. Besides, unbalanced nutrient supply leads to low growth and development of plant, soil deterioration and poor environmental health. Methods: The field experiment was conducted with rice variety PR-121 using 4 establishment methods (transplanting, system of rice intensification, direct seeded rice and wet-direct seeded rice) and 5 nutrient management practices (100% RDF, 75% RDF+FYM (equiv. to 25% N), 150% RDF, RDF (LCC based N application) and RDF+5 t FYM) in split plot design with three replication. Result: Results revealed that the highest value of plant height was recorded under transplanting method while the maximum value of number of tillers m-2, dry matter accumulation crop and relative growth rate was found under direct seeded method of rice establishment over other establishment methods at all the stages of crop growth during both the years of study. Application of 150% RDF recorded the highest value of plant height, number of tillers m-2, dry matter accumulation, crop growth rate and relative growth rate on most of the crop growth stages during both the years of study compared to remaining nutrient management practices but found statistically on par with application of RDF+5 t FYM.