Evaluation of soil loss severity and ecological restoration approach for sustainable agriculture in the Hindu Kush, Karakoram and Himalaya region

Soil erosion has resulted in removal of the topsoils containing fine soil particles and plant nutrients, causing decrease in soil fertility in the Hindu Kush, Karakoram and Himalaya(HKH) region. The existing production of cereal crop grains has been reduced to one third of the potential crop grains production owing to land degradation and poor farming practices. It is necessary to assess risk of soil loss and identify appropriate controlling measures to address issues of low agriculture productivity and water insecurity in the region. In the present study, severity of soil loss was predicted using Revised Universal Loss Equation(RUSLE) and ecological measures were identified for sustainable mountain agriculture in the HKH region of Upper Indus Basin, Pakistan. Overall 62.6% area was found to have very low risk of soil loss, i.e., <5 t/(ha·yr), 15.8% area low risk, i.e., 5-25 t/(ha·yr) and 7.5% area moderate risk, i.e., 25-50 t/(ha·yr) in the region. The risk was high, i.e., 50-100 t/(ha·yr) and very high, i.e., >100 t/(ha·yr) in about 6.8% and 7.4% areas respectively. The mean rate of soil loss was about 41.9 t/(ha·yr) in the Hindu Kush, 31.1 t/(ha·yr) in the Himalayas, 18.8 t/(ha·yr) in the Karakoram and overall 29.7 t/(ha·yr) in the three HKH ranges. As such no considerable measures have been adopted by the communities for restoration of the degraded areas except raising fruit/farm trees and supporting limited social forestry for their livelihoods. The slopes cleared for cultivation and susceptible to erosion may be stabilized through sowing/planting of multi-purpose plant species and formation of proper bench terraces. The conservation of forest ecosystem and pastures at higher elevations would help in reducing overland water flow, risk of flash flood hazard and minimizing sediment loads in the downstream. It is essential to adopt site-specific resource conservation techniques and restore possible ecosystem health for sustainable agriculture and economic development in the region in future.

Genetics of biochemical attributes regulating morpho-physiology of upland cotton under high temperature conditions

Background Cotton is a strategically important fibre crop for global textile industry.It profoundly impacts several countries’industrial and agricultural sectors.Sustainable cotton production is continuously threatened by the unpre-dictable changes in climate,specifically high temperatures.Breeding heat-tolerant,high-yielding cotton cultivars with wide adaptability to be grown in the regions with rising temperatures is one of the primary objectives of modern cotton breeding programmes.Therefore,the main objective of the current study is to figure out the effective breed-ing approach to imparting heat tolerance as well as the judicious utilization of commercially significant and stress-tolerant attributes in cotton breeding.Initially,the two most notable heat-susceptible(FH-115 and NIAB Kiran)and tolerant(IUB-13 and GH-Mubarak)cotton cultivars were spotted to develop filial and backcross populations to accom-plish the preceding study objectives.The heat tolerant cultivars were screened on the basis of various morphological(seed cotton yield per plant,ginning turnout percentage),physiological(pollen viability,cell membrane thermostabil-ity)and biochemical(peroxidase activity,proline content,hydrogen peroxide content)parameters.Results The results clearly exhibited that heat stress consequently had a detrimental impact on every studied plant trait,as revealed by the ability of crossing and their backcross populations to tolerate high temperatures.However,when considering overall yield,biochemical,and physiological traits,the IUB-13×FH-115 cross went over particularly well at both normal and high temperature conditions.Moreover,overall seed cotton yield per plant exhibited a posi-tive correlation with both pollen viability and antioxidant levels(POD activity and proline content).Conclusions Selection from segregation population and criteria involving pollen viability and antioxidant levels concluded to be an effective strategy for the screening of heat-tolerant cotton germplasms.Therefore,understanding acquired from this study can assist breeders identifying traits that should be prioritized in order to develop climate resilient cotton cultivars.

Quantitative and Qualitative Responses of Hydroponic Tomato Production to Different Levels of Salinity

From economic and nutritional points of view,tomato is,historically,considered one of the most important crops.Without significant yield reduction,most commercial cultivars of tomato crops are sensitive to moderate levels of salinity.However,high levels of salt stress can negatively affect the yield and quality of tomato fruits.Therefore,this study was conducted to evaluate the yield and fruit quality of three tomato cultivars(Forester,Ghandowra-F1,and Feisty-Red)cultivated hydroponically,under three different levels of nutrient solution salinity.Evaluation of tomato fruits was performed based on quantity(number and weight of fruits,and total fruit yield),physical quality(color andfirmness),and chemical quality(refractometric index“Brix”,pH,EC,K^(+),Na^(+),and NO_(3)-).Experiments were conducted using three salinity levels of the nutrient solution with electrical conductivity values(dSm^(-1))of 2.5(control),6.0,and 9.5.Results showed that the studied tomato cultivars were significantly influenced by high salinity(9.5 dSm^(-1))in comparison to the low(2.5 dSm^(-1))and medium(6.0 dSm^(-1))levels of salinity.On average,the highest fruit weight per plant of 1944.84 g and total fruit yield of 4.42 kgm^(-2) were observed at the low salinity level;however,no significant differences were obtained in the two yield factors(single fruit weight and total fruit yield)for the low and medium salinity levels.On the other hand,a significant reduction in tomato yield(31%)was associated with the high salinity level compared to the yield at low and medium salinity levels.Results of physical quality parameters showed highly significant differences among all salinity levels.On average,the maximum value of color change(1.72)was associated with the medium salinity level,and the maximum value offirmness(9.61 Ncm^(-1))was recorded at the high salinity level.Salinity levels and tomato cultivars introduced significant differences in chemical quality parameters;however,no significant differences in these parameters were attributed to the low and medium salinity levels.The maximum value of pH was recorded for the combination of medium salinity and Forester cultivar.Moreover,the maximum values of Brix,EC,K^(+),Na^(+),and NO_(3)^(-) were recorded for the Ghandowra-F1 cultivar at the high salinity level.Unlike the Feisty-Red,the performance of the Forester and Ghandowra-F1 cultivars was found to be acceptable at the tested medium salinity level(6.0 dSm^(-1)).

Characterization and screening of cotton(Gossypium hirsutum L.)germplasm for leafhopper(Amrasca biguttula biguttula(Ishida))resistance

Background Cotton(Gossypium hirsutum L.)is one of the most significant fibre and cash crops and plays an important role in Indian industrial and agricultural economies.However,over the years quantity and quality have been hampered by the pest leafhopper.Leafhopper alone has been shown to cause yield losses of up to 40%.In this study,screening and evaluation were performed to identify and categorize 100 cotton genotypes along with 5 checks as resistant,moderately resistant,sensitive and highly sensitive to leafhoppers.Results A total of hundred genotypes were evaluated along with five checks for leafhopper resistance.Based on the screening results,a total of 19 genotypes were resistant to leafhoppers,which was on par with the findings of the check KC 3.The contents of total soluble sugar,total soluble protein,and total free amino acids were significantly positively correlated with the mean grade,whereas total phenols content and trichome density were significantly negatively correlated with the susceptibility grade.However,based on screening and biochemical analysis,the genotypes KC 2,JR-23,Samaru-26-T,D 4,TCH 1728,RS 253,and B-61-1862 exhibited high resistance to leafhopper.Conclusion According to the findings of this study,choosing genotypes with high total phenolics content together with high trichome density and low contents of total soluble sugar,total soluble protein,and free amino acids may aid in the development of resistant genotypes.

Trehalose:A sugar molecule involved in temperature stress management in plants

Trehalose(Tre)is a non-reducing disaccharide found in many species,including bacteria,fungi,invertebrates,yeast,and even plants,where it acts as an osmoprotectant,energy source,or protein/membrane protector.Despite relatively small amounts in plants,Tre concentrations increase following exposure to abiotic stressors.Trehalose-6-phosphate,a precursor of Tre,has regulatory functions in sugar metabolism,crop production,and stress tolerance.Among the various abiotic stresses,temperature extremes(heat or cold stress)are anticipated to impact crop production worldwide due to ongoing climate changes.Applying small amounts of Tre can mitigate negative physiological,metabolic,and molecular responses triggered by temperature stress.Trehalose also interacts with other sugars,osmoprotectants,amino acids,and phytohormones to regulate metabolic reprogramming that underpins temperature stress adaptation.Transformed plants expressing Tre-synthesis genes accumulate Tre and show improved stress tolerance.Genome-wide studies of Tre-encoding genes suggest roles in plant growth,development,and stress tolerance.This review discusses the functions of Tre in mitigating temperature stress—highlighting genetic engineering approaches to modify Tre metabolism,crosstalk,and interactions with other molecules—and in-silico approaches for identifying novel Tre-encoding genes in diverse plant species.We consider how this knowledge can be used to develop temperature-resilient crops essential for sustainable agriculture.

Evaluating the Potential of Nitrofurantoin and Fosfomycin for E.coli UTIs: A Susceptibility Study

This study was designed to find the susceptibility of Nitrofurantoin and Fosfomycin among urinary isolates of Escherichia.coli.Four hundred(400)urine samples were collected for susceptibility of nitrofurantoin and fosfomycin among urinary isolates of E.coli.All indoor and outdoor patients'urinary samples yielded growth of E.coli.Mid-stream urine specimens were inoculated on blood agar and CLED agar and incubated at 35±2°C.Growth was observed,and Escherichia coli was identified by Gram staining,Catalase,Motility test and API 20E(Bio murex)as per standard procedure.Antimicrobial susceptibility testing of isolates for nitrofurantoin and fosfomycin was carried out by the modified Kirby-Bauer disc diffusion method according to CLSI guidelines ATCC 25922.E.coli was used as a quality control strain.A total of 400 samples were tested susceptibility of nitrofurantoin and fosfomycin among urinary isolates of E.coli during this period.A total of 400 samples yielded the growth of E.coli,out of which 178(44.5%)were male and 222(55.5%)were female samples.Among males,18(10%)were tolerant to nitrofurantoin,and 2(1.1%)were tolerant to fosfomycin.Among females,9(4.09%)were susceptible to nitrofurantoin while 6(2.72%)were susceptible to fosfomycin.Among age groups below 45 years old,6(4.76%)were tolerant to nitrofurantoin,and 2(1.58%)were sensitive to fosfomycin.Between 46-66 years old,4(2.81%)were sensitive to nitrofurantoin,and 3(2.11%)were sensitive to fosfomycin.Between 67-90 years old,17(12.87%)were sensitive to nitrofurantoin,and 4(3.03%)were tolerant to fosfomycin.Fosfomycin and nitrofurantoin showed good susceptibility in urinary isolates of E.coli and can be used empirically in our setup.

Targeting Cancers: Uncovering the Potential Roles of Potato Tissue Culture as Anti-Cancer Agents - A Secondary Publication

Plant tissue culture is a technique that enhances the quality and quantity of potatoes. Potatoes are a significant crop and are primarily used in the world. It is a staple food in many countries, where millions of tonnes are produced annually. It is an essential source of many nutrients, such as proteins, carbohydrates, vitamins, and beta-carotene. In addition, potatoes are being used as therapeutic agents against cancer and other human diseases as well. Potatoes are on the third list after wheat and rice. To overcome food shortages and malnutrition, there are two methods used for producing potatoes: the first is sexual, which is seed propagation, and the second is asexual, which is plant tissue culture propagation. Conventional potato breeding is a uniform method, but it is unsafe because there is a risk of pathogen attack. In a laboratory setting, the tissue culture of potatoes produced millions of plants with nutrient-rich medium under controlled environmental conditions that prevent pest attacks. Some environmental stresses, such as salinity and water scarcity, affect potato yield and production;however, applying nanoparticles like organic, inorganic, and silicon dioxide enhances potato quality and combats stress. Biotechnology has proven to be helpful in addressing all these issues. This review discusses the significance of potatoes, their production through the tissue culture technique, and the application of nanoparticles to improve the growth, and impact of potatoes on human health.

Study on the Policies,Science and Technology Support to Impel the Development of Recreational Agriculture in Hainan

The current situation of the recreational agriculture development in Hainan was analyzed. The problems of imperfect security system,unsound policies and regulations,scant government support,low enthusiasm for developing recreational agriculture,lacking science and technology support and less special competitive products in Hainan were discussed. Through the reference of foreign countries and Taiwan Region policy support and legislative experience on recreational agriculture,it was recommended to perfect the policy system,develop the leading role of the government,enhance the legislation and supervision,pay attention to science and technology support,in order to promote the healthy sustainable development of recreational agriculture in Hainan.

Introgression of sharp eyespot resistance from Dasypyrum villosum chromosome 2VL into bread wheat

Wheat sharp eyespot, a stem disease caused by the soilborne fungus Rhizoctonia cerealis van der Hoeven,has become a threat to wheat production worldwide. Exploiting resistance resources from wild relatives of wheat is a promising strategy for controlling this disease. In this study, a new wheat–Dasypyrum villosum T2DS·2V#4L translocation line in the background of Chinese Spring(CS) showed stable resistance to R. cerealis. Introgression of the T2DS·2V#4L chromosome into wheat cultivar Aikang 58 by backcrossing produced a marked increase in sharp eyespot resistance in NIL-T2DS·2V#4L in comparison with NILT2DS·2DL, and no detrimental effects of 2V#4L on agronomic traits were observed in the BC2F2, BC2F2:3,and BC2F2:4generations. Flow-sorted sequencing of 2V#4L yielded 384.3 Mb of assembled sequence, and8836 genes were predicted of which 6154 had orthologs in at least one of the 2AL, 2BL, and 2DL arms of CS, whereas 1549 genes were unique to 2V#4L. About 100,000 SNPs were detected in genes of 2V#4L and2DL in 10 sequenced bread wheat cultivars. A Kompetitive Allele Specific Polymerase chain reaction and30 conserved ortholog sequence markers were developed to trace the 2V#4L chromatin in wheat backgrounds. T2DS·2V#4L compensating translocation lines represent novel germplasm with sharp eyespot resistance and the markers will allow rapid detection in breeding programs.

Past and recent advances in sugarcane cytogenetics

The Saccharum genus comprises species with large and variable chromosome numbers, leading to challenges in genomic studies and breeding improvement. Cytogenetics, including classical and molecular approaches, has played a central role in deciphering the genome structure, classification, and evolution of the genus Saccharum. The application of fluorescence in situ hybridization using oligonucleotide probes significantly improved our understanding of the complex genomes of Saccharum species. This paper reviews the application and progress of cytogenetic techniques in Saccharum. Future applications of cytogenetics are discussed, as they could benefit both genomic studies and breeding of sugarcane as well as other plants with complex genomes.

Influence of Various Hydrocolloids on Suspension Stability of Chia Seeds (Salvia hispanica L.) in Mango Beverage and Mango Flavored Beverage

With the developing of juices and beverages industry, the processors need to bring new nutritional fortified products to capture the market as per the demand of the consumer who needs healthier product. Thus, this study aimed to the production of mango beverage and mango flavored beverage fortified with chia seeds;evaluate the chemical properties of chia seeds and study the effect of adding carboxymethyl cellulose, xanthan gum and low acyl gellan gum at the concentrations of 0.05% and 0.1% on the stability of suspension chia seeds in beverage during storage at ambient temperature for six months. Viscosity, color, zeta potential, suspension of seeds and organoleptic properties were evaluated. Results showed that chia seeds were rich in protein, omega-3 fatty acids and dietary fiber. The addition of 0.05% gellan gum led to improved appearance attributes and the highest stability of suspension of chia seeds for six months, and was the sample which scored highest for overall acceptability compared to the other samples of beverages. Results indicated that using chia seeds with the addition of 0.05% low acyl gellan gum led to the production of fortified mango beverage and mango flavored beverage with high stability for six months.

Cassava Groundnut Intercropping: A Sustainable Land Management Practice for Increasing Crop Productivity and Organic Carbon Stock on Smallholder Farms

Cassava-groundnut intercropping is not a common practice among smallholder farmers in Sierra Leone even though both crops are well suited for intercropping. On-farm trials were conducted in three locations (Bai Largor, Bassah, and Njala Kanima) in the Moyamba district during the 2021 cropping season to investigate the efficacy of cassava-groundnut intercropping for increasing crop productivity and soil organic carbon stock on smallholder farms in the Moyamba district, Southern Sierra Leone. The experimental design was a randomized complete block design in three replications with treatments of sole groundnut, sole cassava and cassava-groundnut intercropping. Data on the yield and yield components of cassava and groundnut were analysed using the PROC MIXED procedure of SAS 9.4 and means were compared using the standard error of difference (SED). The above-ground biomass, number of roots per plant, and fresh root yield of cassava were not significantly (p > 0.05) affected by the cassava-based cropping system. Averaged across locations, intercropping cassava with groundnut decreased the above-ground biomass, the number of roots per plant, and fresh root yield of cassava by 17%, 11%, and 17%, respectively. The above-ground biomass, number of pods per plant and fresh pod yield of groundnut were significantly (p 1), the highest net revenue and benefit-cost ratio. The benefit-cost ratio was also favourable for the sole cassava (BCR > 1) but not favourable for the sole groundnut (BCR < 1). Averaged across locations, intercropping cassava with groundnut increased the benefit-cost ratio by 121% and 13% when compared to the sole groundnut and sole cassava. In the event of a 40% yield loss for the cassava and groundnut, the benefit-cost ratio was favourable (1.12) only for the cassava groundnut intercropping system. The net soil organic carbon stock was favourable only for the cassava-groundnut intercrop. Averaged across locations, the net soil organic carbon for the cassava-groundnut intercropping increased by 3.4% when compared to the baseline within one cropping cycle of the cassava (12 months). The results confirm that cassava-groundnut intercropping is a sustainable land management practice that could enhance crop productivity and soil organic carbon stock on smallholder farms.

Corrigendum to“Introgression of sharp eyespot resistance from Dasypyrum villosum chromosome 2VL into bread wheat”[Crop J.11(2023)1512–1520]

The authors regret to report some missing information in the authorship and associated changes of the paper.On page 1512,the author information reads:“Caiyun Liu a,Wei Guo a,Yang Wang b,Bisheng Fu a,Jaroslav Dolezel c,Ying Liu a,Wenling Zhai a,Mahmoud Said c,d,István Molnár c,d,e,Katerina Holušovác,Ruiqi Zhang b,*,Jizhong Wu a,f,g,*”.It should be changed to“Caiyun Liu a,1,Wei Guo a,1,Yang Wang b,Bisheng Fu a,Jaroslav Dolezel c,Ying Liu a,Wenling Zhai a,Mahmoud Said c,d,István Molnár c,d,e,Katerina Holušovác,Ruiqi Zhang b,*,Jizhong Wu a,f,g,*”.On page 1512 in the footnote,the following sentence should be added below the corresponding authors’information:1 These authors contributed equally to this work.The correction has been updated above.The authors would like to apologize for any inconvenience caused.

First Record of Pristomerus pallidus (Hymenoptera: Ichneumonidae: Cremastinae) (Kriechbaumer) Parasitizing Hellula undalis (F.) (Lepidoptera: Pyralidae) in Crucifer Crop in Senegal

Cabbage is today an economically important crop grown in more than 90 countries around the world. Production is constantly threatened by pests including the cabbage webworm, Hellula undalis (F.) (Lepidoptera: Pyralidae) which just one or two larvae can cause severe damage by infesting the growing points or shoots of young plants. Hellula undalis is difficult to control by the use of chemical insecticides. The establishment of effective biological control is needed. The parasitoid species Pristomerus pallidus (Hymenoptera: Ichneumonidae: Cremastinae) was recorded for the first time in Senegal on larvae of Hellula undalis from cabbage fields infested with H. undalis. Laboratory observed parasitism was 7.4%. This is the first record of Pristomerus pallidus parasitizing Hellula undalis from Senegal. Furthermore, studies on the potential regulation of Hellula undalis under controlled and field conditions need to be evaluated for utilizing this parasitoid as a biocontrol agent against the cabbage webworm. .

Genetic Variability, Heritability and Correlation of Some Morphological and Yield Components Traits in Potato (Solanum tuberosum L.) Collections

The study was conducted with the main objective to evaluate the genetic variability, heritability, and clustering pattern exploration of morphological and yield related traits in potato (Solanum tuberosum L.) collections in the bimodal rainfall agroecological zone of Cameroon using a Randomized Complete Block Design (RCBD) with three replications. The data obtained on morphological and yield traits were subjected to analysis of variance (ANOVA). The results showed that the viability rate of the collections varied from 77.78% to 96.55% respectively for the Maffo and Desiree collections, while the greatest number of tubers per plant varied from 4 to 18 respectively for Synergie and Desiree. The emergence rate varies from 60% to 1.66% respectively for Maffo et Doza collections. However, Desiree presents the highest TL (96.55) while Maffo shows the lowest value (77.78%). The yield per hectare varied from 1.14 to 9.3 t/h for Maffo and Doza respectively. For all the characteristics observed, Phenotypic Coefficients of Variation (PCV) were higher than Genotypic Coefficients of Variation (GCV) suggesting the role of environment in the expression of traits under observation. The highest GCV and PCV 47.55 and 58.94 respectively were observed for Diameter at the collar (DC). Most of the traits showed high GAM (>20%)) except Average Tuber Length (ATL) with a moderate value (19.8). In terms of vegetative development, the Desiree variety showed the highest performance. Based on the growth and yield results, Doza seems to be the most recommendable crop in the study area.

少免耕及秸秆还田小麦间作玉米的碳排放与水分利用特征

【目的】利用间作和保护性耕作对土壤碳减排及水分高效利用的潜力,将二者集成于同一系统中以发挥各自的优势并催生彼此间的协同效应,从而建立减排与节水双赢的间作高效种植模式。【方法】以河西绿洲灌区长期规模化种植的小麦间作玉米为研究对象,集成应用保护性耕作的理论与技术,利用带状耕作和秸秆覆盖建立免耕立茬(NTSSI)、免耕秸秆覆盖(NTSI)、少耕秸秆翻压(TISI)和传统收割(CTI)4种处理,并以传统收割单作小麦(SW)和单作玉米(SM)作为对照,系统研究了不同处理土壤呼吸与作物耗水状况。应用土壤呼吸测定系统EGM-4(environmental gas monitor-4,UK,PP system)测定土壤呼吸速率,以此计算不同处理生育期内土壤碳排放总量。用产量与耗水和土壤碳排放量与耗水两种方法计算水分利用效率,客观评价间作系统的水分利用状况。【结果】不同种植模式中,单作玉米土壤呼吸速率最大(1.57μmol CO_2·m^(-2)·s^(-1)),间作次之(0.83μmol CO_2·m^(-2)·s^(-1)),单作小麦最小(0.72μmol CO_2·m^(-2)·s^(-1));4种秸秆还田方式中,NTSI处理土壤呼吸速率最低,2011与2012年分别较CTI降低了20.4%和11.9%,由此减少碳排放量12.4%。在间作中集成应用带状耕作和秸秆覆盖能有效降低系统耗水总量、增加产量、提高水分利用效率(WUEGY),与CTI处理相比,NTSI处理平均减少耗水量达4.1%,增产29.7%,水分利用效率提高15.6%。同时,间作系统的单位耗水碳排放平均降低了5.9%,碳排放效率提高了28.2%。【结论】小麦间作玉米与保护性耕作结合,并集成应用带状耕作及秸秆覆盖技术可使系统的产量、碳排放和耗水得到有效协调,能促进耗水更多转化为作物产量并降低在该转化过程中产生的碳排放,实现碳减排与水分高效利用的协同促进。

生物质炭添加对华南双季稻田碳排放强度的影响

中国农田有机物料资源化利用是一项巨大挑战。为研究生物质炭农田施用的生态效应,探讨华南双季稻田碳排放强度(greenhouse gas intensity,GHGI)对生物质炭添加的响应,开展了基于静态箱-气相色谱法的连续两年野外观测。田间试验共设6个处理,即当地农民习惯(CK,化肥,无稻草还田),3个不同用量生物质炭添加处理,即BC1(5 t/hm2)、BC2(10 t/hm2)和BC3(20 t/hm2),和2个稻草还田处理(直接还田和稻草+腐熟剂还田)。结果表明,相比当地农民习惯和稻草还田处理生物质炭添加有效抑制了双季稻田温室气体排放(平均降低温室气体排放当量49.87%),显著降低了土壤容重,增强作物的碳氮养分吸收能力,稳定了水稻产量(平均增产3.54%),降低了稻田碳排放强度(平均降低52.13%)。4个生长季平均而言,相比CK、RS和RI,生物质炭3个处理分别降低稻田100a尺度上温室气体排放当量27.53%,58.65%和63.43%(P<0.05),分别增产3.21%,5.11%和2.29%(P>0.05),进而分别降低100a尺度上GHGI 30.57%,61.00%和64.82%(P<0.05),综合而言,BC3具有较好的减排增产潜力。相关矩阵和主成分分析可视化表达了在生物炭添加影响下,稻田碳排放强度与水稻生长参数及土壤理化特性的关系。生物质炭添加影响着水稻产量、收获指数、土壤有机质、总碳和植株吸氮量等环境变量的分布。通过多元决策回归树分析,发现可通过水稻收获指数(>0.5)定量判别其碳排放强度。该研究结果表明,通过优化田间管理,适量生物质炭回田(20 t/hm2)利用是增强土壤固碳、稳定水稻产量、降低稻田碳排放强度和应对气候变化不利影响的可行途径。该研究可为中国秸秆资源科学利用提供基础研究案例。

致病疫霉抗药性、交配型和适合度

在离体条件下 ,我国马铃薯和番茄上 6 2株致病疫霉中对甲霜灵和恶霜灵抗性菌株占 11.2 9% ,平均抗性水平 15 0 2 2倍和 2 4 733倍 ,未发现抗霜脲氰菌株和抗烯酰吗啉菌株。在活体条件下 ,比利时马铃薯上 6 6株致病疫霉中对甲霜灵和恶霜灵抗性菌株占 2 7.3% ,河北省围场、崇礼马铃薯上 2 17株中对甲霜灵和恶霜灵抗性菌株分别占 2 9.0 %和 32 .7% ,河北省徐水番茄上 88株中仅发现 1株抗甲霜灵和恶霜灵。比利时马铃薯上的 6 6株中 4株为 A2交配型 ,占 6 .1% ,1株交配型为 A1A2 ,抗甲霜灵。围场、崇礼马铃薯上的 73株中 6株为 A2交配型 ,占 8.2 % ,6株 A2交配型中 3株抗甲霜灵和恶霜灵。徐水番茄上的 4 4株中 3株 A2交配型占 6 .8%。致病疫霉对甲霜灵和恶霜灵具有交互抗性 ,而2药与霜脲氰或烯酰吗啉之间无交互抗性关系。由于抗性菌株的产孢能力明显较高 。

世界粮食研究模型在黑龙江省作物产量预报中的应用

在现有研究成果的基础上,提出世界粮食研究(WOFOST)模型在黑龙江省四大作物产量预报应用中的参数分区处理方法,运用WOFOST的模拟产量和趋势产量对黑龙江省四大作物产量进行了预测分析。研究表明:该方法效果理想、可行,具有理论研究和实际应用价值,克服了只用一组参数在复杂气候区域进行作物产量模拟的局限性,拓宽了WOFOST模型在复杂气候条件下的应用领域。