Applying plant-based irrigation scheduling to assess water use efficiency of cotton following a high-biomass rye cover crop

[Background] This study addressed the potential of combining a high biomass rye winter cover crop with predawn leaf water potential (ΨPD) irrigation thresholds to increase agricultural water use efficiency (WUE) in cotton. To this end, a study was conducted near Tifton, Georgia under a manually-controlled, variable-rate lateral irrigation system using a Scholander pressure chamber approach to measure leaf water potential and impose varying irrigation scheduling treatments during the growing season. ΨPD thresholds were − 0.4 MPa (T1), − 0.5 MPa (T2), and − 0.7 MPa (T3). A winter rye cover crop or conventional tillage were utilized for T1-T3 as well.

[Results] Reductions in irrigation of up to 10% were noted in this study for the driest threshold (− 0.7 MPa) with no reduction in lint yield relative to the − 0.4 MPa and − 0.5 MPa thresholds. Drier conditions during flowering (2014) limited plant growth and node production, hastened cutout, and decreased yield and WUE relative to 2015.

[Conclusions] We conclude that ΨPD irrigation thresholds between − 0.5 MPa and − 0.7 MPa appear to be viable for use in a ΨPD scheduling system with adequate yield and WUE for cotton production in the southeastern U.S. Rye cover positively impacted water potential at certain points throughout the growing season but not yield or WUE indicating the potential for rye cover crops to improve water use efficiency should be tested under longer-term production scenarios.

[Title] Applying plant-based irrigation scheduling to assess water use efficiency of cotton following a high-biomass rye cover crop

[Authors] MEEKS Calvin D., SNIDER John L., CULPEPPER Stanley and HAWKINS Gary
Journal of Cotton Research 3, Article number: 16 (2020)

Genotypic variance in 13C-photosynthate partitioning and within-plant boll distribution in cotton

[Background] Photosynthate partitioning and within-plant boll distribution play an important role in yield formation of cotton; however, if and how they interact to mediate yield remains unclear. The objective of this study was to investigate the genotypic variance in photosynthate partitioning and within-plant boll distribution, with a focus on their interactions with regard to yield and yield components. A field experiment was conducted in the Yellow River region in China in 2017 and 2018 using a randomized complete block design with three replicates. Photosynthate partitioning of three commercial cultivars (DP 99B, Lumianyan 21 and Jimian 169), varying in yield potential, to different organs (including bolls) at early flowering, peak flowering, and peak boll-setting stages, as well as within-plant boll distribution at harvest, and their effects on yield formation were examined.

[Results] Lint yield of Jimian 169 was the highest, followed by Lumianyan 21 and DP 99B. Similar differences were observed in the number of inner bolls and boll weight among the three cultivars. J169 partitioned significantly more photosynthate to the fruit and fiber than Lumianyan 21 and DP 99B and allocated over 80% of assimilates to the inner bolls. Additionally, Lumianyan 21 allocated a higher proportion of photosynthate to bolls and fiber, with 12.5%–17.6% more assimilates observed in the inner bolls, than DP 99B.

[Conclusions] Genotypic variance in lint yield can be attributed to differences in the number of inner bolls and boll weight, which are affected by photosynthate partitioning. Therefore, the partitioning of photosynthate to fiber and inner bolls can be used as an important reference for cotton breeding and cultivation.

[Title] Genotypic variance in 13C-photosynthate partitioning and within-plant boll distribution in cotton

[Authors] NIE Junjun, QIN Dulin, MAO Lili, LIU Yanhui, DONG Hezhong, SONG Xianliang and SUN Xuezhen

Journal of Cotton Research 3, Article number: 15 (2020)

Membrane lipid raft organization during cotton fiber development

Journal of Cotton Research

[Background] Cotton fiber is a single-celled seed trichome that originates from the ovule epidermis. It is an excellent model for studying cell elongation. Along with the elongation of cotton fiber cell, the plasma membrane is also extremely expanded. Despite progress in understanding cotton fiber cell elongation, knowledge regarding the relationship of plasma membrane in cotton fiber cell development remains elusive.

[Methods] The plasma membrane of cotton fiber cells was marked with a low toxic fluorescent dye, di-4-ANEPPDHQ, at different stages of development. Fluorescence images were obtained using a confocal laser scanning microscopy. Subsequently, we investigated the relationship between lipid raft activity and cotton fiber development by calculating generalized polarization (GP values) and dual-channel ratio imaging.

[Results] We demonstrated that the optimum dyeing conditions were treatment with 3 μmol·L− 1 di-4-ANEPPDHQ for 5 min at room temperature, and the optimal fluorescence images were obtained with 488 nm excitation and 500–580 nm and 620–720 nm dual channel emission. First, we examined lipid raft organization in the course of fiber development. The GP values were high in the fiber elongation stage (5–10 DPA, days past anthesis) and relatively low in the initial (0 DPA), secondary cell wall synthesis (20 DPA), and stable synthesis (30 DPA) stages. The GP value peaked in the 10 DPA fiber, and the value in 30 DPA fiber was the lowest. Furthermore, we examined the differences in lipid raft activity in fiber cells between the short fiber cotton mutant, Li-1, and its wild-type. The GP values of the Li-1mutant fiber were lower than those of the wild type fiber at the elongation stage, and the GP values of 10 DPA fibers were lower than those of 5 DPA fibers in the Li-1 mutant.

[Conclusions] We established a system for examining membrane lipid raft activity in cotton fiber cells. We verified that lipid raft activity exhibited a low-high-low change regularity during the development of cotton fiber cell, and the pattern was disrupted in the short lint fiber Li-1 mutant, suggesting that membrane lipid order and lipid raft activity are closely linked to fiber cell development.

[Title] Membrane lipid raft organization during cotton fiber development

[Authors] XU Fan, SUO Xiaodong, LI Fang, BAO Chaoya, HE Shengyang, HUANG Li & LUO Ming

Screening and evaluation of reliable traits of upland cotton (Gossypium hirsutum L.) genotypes for salt tolerance at the seedling growth stage

Journal of Cotton Research

[Background] Salt stress significantly inhibits the growth, development, and productivity of cotton because of osmotic, ionic, and oxidative stresses. Therefore, the screening and development of salt tolerant cotton cultivars is a key issue towards sustainable agriculture. This study subjected 11 upland cotton genotypes at the seedling growth stage to five different salt concentrations and evaluated their salt tolerance and reliable traits.

[Results] Several morpho-physiological traits were measured after 10 days of salinity treatment and the salt tolerance performance varied significantly among the tested cotton genotypes. The optimal NaCl concentration for the evaluation of salt tolerance was 200 mmol·L 1. Membership function value and salt tolerance index were used to identify the most consistent salt tolerance traits. Leaf relative water content and photosynthesis were identified as reliable indicators for salt tolerance at the seedling stage. All considered traits related to salt tolerance indices were significantly and positively correlated with each other except for malondialdehyde. Cluster heat map analysis based on the morpho-physiological salt tolerance-indices clearly discriminated the 11 cotton genotypes into three different salt tolerance clusters. Cluster I represented the salt-tolerant genotypes (Z9807, Z0228, and Z7526) whereas clusters II (Z0710, Z7514, Z1910, and Z7516) and III (Z0102, Z7780, Z9648, and Z9612) represented moderately salt-tolerant and salt-sensitive genotypes, respectively.

[Conclusions] A hydroponic screening system was established. Leaf relative water content and photosynthesis were identified as two reliable traits that adequately represented the salt tolerance of cotton genotypes at the seedling growth stage. Furthermore, three salt-tolerant genotypes were identified, which might be used as genetic resources for the salt-tolerance breeding of cotton.

[Title] Screening and evaluation of reliable traits of upland cotton (Gossypium hirsutum L.) genotypes for salt tolerance at the seedling growth stage
[Authors] SIKDER Ripon Kumar, WANG Xiangru, JIN Dingsha, ZHANG Hengheng, GUI Huiping, DONG Qiang,  PANG Nianchang, ZHANG Xiling & SONG Meizhen

Soil replacement combined with subsoiling improves cotton yields

[Background] Long-term rotary tillage has led to the deterioration of cotton production in northern China. This deterioration is due to the disturbance of topsoil, a dense plough pan at the 20–50 cm depth, and the decreased water storage capacity. A 2-yr field experiment was performed from 2014 to 2015 to explore a feasible soil tillage approach to halting the deterioration. The experiment consisted of four treatments: replacing the topsoil from the 0–15 cm layer with the subsoil from the 15–30 cm layer (T1); replacing the topsoil from the 0–20 cm layer with the subsoil from the 20–40 cm layer and subsoiling at the 40–55 cm layer (T2); replacing the topsoil from the 0–20 cm layer with the subsoil from the 20–40 cm layer and subsoiling at the 40–70 cm layer (T3); and conventional surface rotary tillage within 15 cm as the control (CK).

[Results] The results indicated that the soil bulk densities at the 20–40 cm layer in T2 were 0.13 g·cm− 3and 0.15 g·cm− 3 lower than those obtained from CK in 2014 and 2015, respectively. The total nitrogen (N) and the available phosphorus (P) and potassium (K) contents from the 20–40 cm layer in T2 and T3 were significantly higher than those in CK and T1. The amount of soil water stored in the 0–40 cm layer of T2 at the squaring stage of cotton was 15.3 mm and 13.4 mm greater than that in CK in 2014 and 2015, respectively, when the weather was dry. Compared with CK, T2 increased cotton lint yield by 6.1 and 10.2 percentage points in 2014 and 2015, respectively, which was due to the improved roots within the 20–60 cm layer, the greater number of bolls per plant and the higher boll weight in the T2 treatment.

[Conclusions] The results suggested that soil replacement plus subsoiling would be a good alternative to current practices in order to break through the bottleneck constraining cotton production in northern China. Replacing the topsoil in the 0–20 cm layer with the soil from the 20–40 cm layer plus subsoiling at the 40–55 cm layer would be the most effective method.

[Title] Soil replacement combined with subsoiling improves cotton yields

[Authors] LI Pengcheng, WANG Shulin, QI Hong, WANG Yan, ZHANG Qian, FENG Guoyi, ZHENG Cangsong, YU Xueke, LIN Yongzeng & DONG Helin

Journal of Cotton Research2019; 2:25

Comparative effects of crop residue incorporation and inorganic potassium fertilization on soil C and N characteristics and microbial activities in cotton field

[Background] Crop residue incorporation into the soil is an effective method to augment soil potassium (K) content, and effects of crop residue and K fertilizer on soil K balance have been compared. However, their influences on other soil characteristics such as carbon (C) and nitrogen (N) characteristics and microbial activities have not been quantified. To address this, field experiments were conducted in 2011 at Dafeng (sandy loam) and Nanjing (clay loam) in China with treatments including blank control without crop residue incorporation and K fertilizer application, 0.9 t·ha− 1 wheat straw incorporation (W1C0), 0.7 t·ha− 1 cotton residue incorporation (W0C1), 0.9 t·ha− 1 wheat straw + 0.7 t·ha− 1 cotton residue incorporation (W1C1) and two K fertilizer rates (150 and 300 kg·ha− 1 (K2O)) during the cotton season.

[Results] Compared with control, K fertilizer treatments did not alter soil water-soluble organic carbon/soil organic carbon (WSOC/SOC) ratio, microbial biomass carbon (MBC)/SOC ratio, MBC/microbial biomass nitrogen (MBN) ratio, water inorganic nitrogen/total nitrogen ratio (WIN/TN), the number of cellulose-decomposing bacteria, or related enzymes activities, however, W0C1, W1C0 and W1C1 treatments significantly increased WSOC/SOC ratio, MBC/SOC ratio and MBC/ MBN ratio, and decreased WIN/TN ratio at both sites. W0C1, W1C0 and W1C1 treatments also increased the number of soil cellulose-decomposing bacteria and activities of cellulase, β-glucosidase and arylamidase. Regarding different crop residue treatments, W1C0 and W1C1 treatments had more significant influences on above mentioned parameters than W0C1 treatment. Moreover, MBC/MBN ratio was the most important factor to result in the differences in the number of cellulose-decomposing bacteria and soil enzymes activities among different treatments.

[Conclusions] This study provided a detailed phenotypic diversity description of a population representing a wide range of upland cotton germplasm. Our findings provide useful information about possible elite fibre quality parents for cotton breeding programs.

[Title] Evaluation of the genetic diversity of fibre quality traits in upland cotton (Gossypium hirsutum L.) inferred from phenotypic variations

[Authors] HU Wei, SUI Ning , YU Chaoran, YANG Changqin, LIU Ruixian and ZHOU Zhiguo

Journal of Cotton Research2019; 2:24

Antioxidant and Physiological Responses of Upland Cotton Accessions Grown Under High-Temperature Regimes

Increased temperature caused by climate change is exerting negative impacts on productivity of cotton crop. Therefore, breeding cultivars tolerant of high temperature are need of the time. Realizing the situation, 154 accessions of upland cotton were sown under alpha lattice design in three replications in two sowing dates. The first sowing date was planned to coincide the flowering stage with maximum annual temperature (± 48 °C) of the region. The data were recorded at appearance of first flower for physiological traits like viability of pollen grains and cell membrane thermostability. Enzymatic and non-enzymatic antioxidants, i.e., peroxidase activity and proline contents were also quantified along with hydrogen peroxide. K-means cluster and biplot analysis revealed the differential response of genotypes. FH-Lalzar, IUB-13, GH-Mubarak and Shahkar exhibited higher values for antioxidants and physiological traits. The yield and fibre quality of these genotypes were also superior as compared to others. It was suggested that diversity in germplasm for aforementioned traits can be utilized in further breeding programs.

  • Sajid Majeed, Tanwir Ahmad Malik, Iqrar Ahmad Rana, Muhammad Tehseen   AzharEmail author

Iranian Journal of Science and Technology, Transactions A: Science

Abstracts of “3rd Sino-Pak ICICBB” Changji, China 4-9 September 2019

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Determination of manganese content in cottonseed meal using near-infrared spectrometry and multivariate calibration

[Background] Manganese (Mn) is an essential microelement in cottonseeds, which is usually determined by the techniques relied on hazardous reagents and complex pretreatment procedures. Therefore a rapid, low-cost, and reagent-free analytical way is demanded to substitute the traditional analytical method.

[Results] The Mn content in cottonseed meal was investigated by near-infrared spectroscopy (NIRS) and chemometrics techniques. Standard normal variate (SNV) combined with first derivatives (FD) was the optimal spectra pre-treatment method. Monte Carlo uninformative variable elimination (MCUVE) and successive projections algorithm method (SPA) were employed to extract the informative variables from the full NIR spectra. The linear and nonlinear calibration models for cottonseed Mn content were developed. Finally, the optimal model for cottonseed Mn content was obtained by MCUVE-SPA-LSSVM, with root mean squares error of prediction (RMSEP) of 1.994 6, coefficient of determination (R2) of 0.949 3, and the residual predictive deviation (RPD) of 4.370 5, respectively.

[Conclusions] The MCUVE-SPA-LSSVM model is accuracy enough to measure the Mn content in cottonseed meal, which can be used as an alternative way to substitute for traditional analytical method.

 [Title] Determination of manganese content in cottonseed meal using near-infrared spectrometry and multivariate calibration

[Authors] En YU, Rubing ZHAO, Yunfei CAI, Jieqiong HUANG, Cheng LI, Cong LI, Lei MEI, Lisheng BAO, Jinhong CHEN & Shuijin ZHU

Journal of Cotton Research. 2019, 2: 12

Effects of mepiquat chloride on yield and main properties of cottonseed under different plant densities

[Background] Cottonseed oil and protein content as well as germination traits are major indicators of seed quality. However, the responses of these indicators to plant density and mepiquat chloride (MC) are still uncertain. To investigate plant density and MC effects on cottonseed yield and main quality parameters, we conducted a two-year field experiment including four plant densities (1.35, 2.55, 3.75 and 4.95 plants·m− 2) and two doses of MC (0 and 135 g·hm− 2) in Dafeng, Jiangsu Province, in 2013 and 2014.

[Results] The application of MC reduced plant height, fruit branch length and fruiting branch number under different plant densities, resulting in a lower and more compact plant canopy. Cottonseed yield showed a nonlinear increase as plant density increasing and achieved the highest value at 3.75 plants·m− 2, regardless of MC application. No significant interactions were found between plant density and MC for cottonseed yield and quality parameters. The 100-seed weight, cottonseed oil content and vigor index significantly decreased as plant density increased, while these parameters significantly increased with MC applying under different plant densities. Seed vigor index was positively correlated with 100-seed weight and seed oil content across different plant densities and MC treatments.

[Conclusions] Thus, application of MC could realize a win-win situation between cottonseed yield and main quality parameters under various densities; and plant density of 3.75 plants·m− 2combined with 135 g·hm− 2 of MC applying is optimal for high cottonseed yield and quality in this cotton production area.


[Title] Effects of mepiquat chloride on yield and main properties of cottonseed under different plant densities

[Authors] ZHAO Wenqing, YAN Qiang, YANG Hongkun, YANG Xiaoni, WANG Leran, CHEN Binglin, MENG Yali and ZHOU Zhiguo

Journal of Cotton Research. 2019; 2:10