Effects on Agronomic Traits,Yield and Benefit of One-year Triple Cropping "Maize-soybean" Strip Intercropping System Under Reduced Fertilizer Application

[Objectives] This study was conducted to investigate the effects on agronomic traits,yield and benefit of one-year triple cropping " maize-soybean" strip intercropping system under reduced fertilizer application. [Methods]A single factor randomized block design was used,and wide and narrow strip intercropping was adopted. Three different fertilization treatments,namely fertilizers for conventional field fertilization( A1),80% A1( A2) and 60% A1( A3) were applied to the field production. The fertilizing sites were about 25 cm away from maize and repeated three times. [Results]Compared with A1,the change laws of the agronomic traits and yield in the A2 and A3 intercropping systems were described as below. Agronomic traits: The plant height became shorter gradually for the spring soybean,but increased gradually for the summer soybean,the bottom pod height gradually reduced,and the node number,pods per plant and seeds per plant increased;and the plant height,ear length,rows per ear,seeds per row and 1 000-seed weight of the spring maize decreased. Yield: The yield of maize as the main crop decreased but not significant,by 3. 20% and 3. 99%,respectively in A2 and A3,both smaller than 5. 00%;the yield of the spring soybean significantly increased by 9. 70% and 11. 84%,respectively;the yield of the summer soybean increased by 5. 18% and 8. 98%,respectively;and the total yield increased by 0. 20% and 0. 92%,respectively. Benefit: The total output value increased by 2. 97 % and 4. 91 %,respectively,and the total benefit increased by 6. 39% and 11. 22%,respectively. [Conclusions] Under a 40% reduction in fertilizer applied in the field,the one-year triple cropping " maize-soybean" strip intercropping system still met the multi-target requirements of increasing grain production and economic benefits,and thus can be promoted and applied in Guangxi.

Telomere-to-telomere assembly of cassava genome reveals the evolution of cassava and divergence of allelic expression

Cassava is a crucial crop that makes a significant contribution to ensuring human food security.However,high-quality telomere-totelomere cassava genomes have not been available up to now,which has restricted the progress of haploid molecular breeding for cassava.In this study,we constructed two nearly complete haploid resolved genomes and an integrated,telomere-to-telomere gap-free reference genome of an excellent cassava variety,‘Xinxuan 048’,thereby providing a new high-quality genomic resource.Furthermore,the evolutionary history of several species within the Euphorbiaceae family was revealed.Through comparative analysis of haploid genomes,it was found that two haploid genomes had extensive differences in linear structure,transcriptome features,and epigenetic characteristics.Genes located within the highly divergent regions and differentially expressed alleles are enriched in the functions of auxin response and the starch synthesis pathway.The high heterozygosity of cassava‘Xinxuan 048’leads to rapid trait segregation in the first selfed generation.This study provides a theoretical basis and genomic resource for molecular breeding of cassava haploids.

Construction of EMS-Induced Peanut Mutant Libraries and Identification of Pod-Related Traits Mutant Lines

Peanut(Arachis hypogaea L.)is an oil and economic crop of vital importance,and peanut pod is the key organ influencing the yield and processing quality.Hence,the Pod-related traits(PRTs)are considered as important agronomic traits in peanut breeding.To broaden the variability of PRTs in current peanut germplasms,three elite peanut cultivars were used to construct Ethyl methane sulfonate(EMS)-induced mutant libraries in this study.The optimal EMS treatment conditions for the three peanut varieties were determined.It was found that the median lethal dose(LD50)of EMS treatment varied greatly among different genotypes.Finally,the EMS-induced peanut mutant libraries were constructed and a total of 124 mutant lines for PRTs were identified and evaluated.Furthermore,“M-8070”,one of the mutant lines for pod constriction,was re-sequenced via high-throughput sequencing technology.The genome-wide variations between“M-8070”and its wild parent“Fuhua 8”(FH 8)were detected.2994 EMS-induced single nucleotide polymorphisms(SNPs)and 1188 insertion-deletions(InDels)between“M-8070”and its wild parent were identified.The predominant SNP mutation type was C/G to T/A transitions,while the predominant InDel mutation type was“1-bp”.We analyzed the distribution of identified mutations and annotated their functions.Most of the mutations(91.68%of the SNPs and 77.69%of the InDels)were located in the intergenic region.72 SNPs were identified in the exonic region,leading to 27 synonymous,43 nonsynonymous and 2 stop-gain variation for gene structure.13 Indels were identified in the exonic region,leading to 4 frame-shift,8 non-frame-shift and 1 stop-gain variations of genes.These mutations may lead to the phenotypic variation of“M-8070”.Our study provided valuable resources for peanut improvement and functional genomic research.

Genetic Diversity,Population Structure,and Genome-Wide Association Study of Seven Agronomic Traits in 273 Diverse Upload Cotton Accessions

Upland cotton(Gossypium hirsutum)is the most important plant producing natural fibers for the textile industry.In this study,we first investigated the phenotypic variation of seven agronomic traits of 273 diverse cotton accessions in the years 2017 and 2018,which were from 18 geographical regions.We found large variations among the traits in different geographical regions and only half of the traits in either years 2017 or 2018 followed a normal distribution.We then genotyped the collection with 81,612 high quality SNPs.Phylogenetic tree and population structure revealed a diverse genetic structure of the core collection,and geographical diversification was an important factor,but account for part of the variances of genetic diversification.We then performed genome-wide association study for the seven traits in the years 2017 and 2018,and the average values of each trait in the two years,respectively.We identified a total of 19 significant marker-trait associations and found that Pollen Ole e 1 allergen/extension could be the candidate gene associated with the fall-off cotton bolls from the last three branches.In addition,large variations were observed for the heritability of traits in the years 2017 and 2018.These results provide new potential candidate genes for further functional validation,which could be useful for genetic improvement and breeding of new cotton cultivars with better agronomic performances.

Rapid gene expression change in a novel synthesized allopolyploid population of cultivated peanut×Arachis doigoi cross by cDNA-SCoT and HFO-TAG technique

AIIopolyploidy has played an important role in plant evolution and heterosis. Recent studies indicate that the process of wide hybridization and （or） polyploidization may induce rapid and extensive genetic and epigenetic changes in some plant species. To better understand the allopolyploidy evolutionism and the genetic mechanism of Arachis interspecific hybridization, this study was conducted to monitor the gene expression variation by cDNA start codon targeted polymorphism （cDNA-SCoT） and cDNA high-frequency oligonucleotide-targeting active gene （cDNA-HFO-TAG） techniques, from the hybrids （F1） and newly synthesized allopolyploid generations （S0-$3） between tetraploid cultivated peanut Zhongkaihua 4 with diploid wild one Arachis doigoi. Rapid and considerable gene expression variations began as early as in the FI hybrid or immediately after chromosome doubling. Three types of gene expression changes were observed, including complete silence （gene from progenitors was not expressed in all progenies）, incomplete silence （gene expressed only in some progenies） and new genes activation. Those silent genes mainly involved in RNA transcription, metabolism, disease resistance, signal transduction and unknown functions. The activated genes with known function were almost retroelements by cDNA-SCoT technique and all metabolisms by cDNA-HFO-TAG. These findings indicated that interspecific hybridization and ploidy change affected gene expression via genetic and epigenetic alterations immediately upon allopolyploid formation, and some obtained transcripts derived fragments （TDFs） probably could be used in the research of molecular mechanism of Arachis allopolyploidization which contribute to thwe genetic diploidization of newly formed allopolyploids. Our research is valuable for understanding of peanut evolution and improving the utilization of putative and beneficial genes from the wild peanut.

The Salt Reduction and Yield Increase Effects of Smashing Ridging Transforming Saline-alkali Land and Its Development Prospects

Using smashing ridging tillage machine and smashing ridging technology invented by the authors, transformation test of saline-alkali land by smashing ridging was conducted respectively in Xinjiang and Shaanxi during 2015 -2016. The results showed, in severe saline-alkali soil of Xin-jiang ,after growing cotton by smashing ridging, total salt in soil decreased by 31.31 %, cotton production increased by 48.80%, and salinity level declined from severe to moderate; in mild saline-alkali soil of Shaanxi, after growing summer corn by smashing ridging, total salt in soil decreased by 42.37%, corn yield increased by 34.83%, salinity degree changed from mild desalination to normal farmland ; in Ningxia, Inner Mongolia 7 Gansu ,Jilin, Henan, Hebei, and so on, smashing ridging tillage practice in different types of saline-alkali land was conducted ; according to the salt reduction and yield increase effects of saline-alkali land after smashing ridging, the development prospect of smashing ridging technique in improvement and application of saline-alkali land was proposed.

Phylogenetic Relationships in Genus Arachis Based on SSR and AFLP Markers

Fourteen wild species of different sections in the genus Arachis and 24 accessions of the AABB allotetraploid A. hypogaea （cultivated peanut） from several countries which belong to different botanical varieties, were analyzed by SSR and AFLP marker systems. The assay-units per system needed to distinguish among all the tested accessions were at least five for SSR or two for AFLP. The genetic distance detected by the SSR markers ranged from 0.09 to 0.95, and the mean was 0.73; and the genetic distance detected by the AFLP markers ranged from 0.01 to 0.79 with an average of 0.42. All the tested peanut SSR primer pairs were multilocus ones, and the amplified fragments per SSR marker in each peanut genome ranged from 2 to 15 with the mean of 4.77. The peanut cultivars were closely related to each other, and shared a large numbers of SSR and AFLP fragments. In contrast, the species in the genus Arachis shared few fragments. The results indicated that the cultivated peanut （A. hypogaea L.） varieties could be partitioned into two main groups and four subgroups at the molecular level, and that A. duranensis is one of the wild ancestors of A. hypogaea. The lowest genetic variation was detected between A. cardenasii and A. batizocoi, and the highest was detected between A. pintoi and the species in the section Arachis. The relationships among the botanical varieties in the cultivated peanut （A. hypogaea L.） and among wild species accessions in section Arachis and those in other sections in the genus Arachis were discussed.

Analysis on Green Development Strategy of Xinjiang Cotton

Through on-the-spot investigation and survey in Xinjiang cotton region and relevant data( containing statistical data,online information and government documents,etc.),the characteristics of water resource,wind-sand disaster,soil salinization,cotton diseases,insect pests and weeds in Xinjiang are studied. It is proposed reasons and specific programmes of green development strategy of Xinjiang cotton,and specific strategies contain ecological water supply,land desertification control,soil improvement,and ecological control of diseases,insect pests and weeds,thereby providing the support for sustainable development of Xinjiang cotton.

A novel long non-coding RNA, DIR, increases drought tolerance in cassava by modifying stress-related gene expression

Cassava is an important tropical cash crop. Severe drought stresses affect cassava productivity and quality, and cause great economic losses in agricultural production. Enhancing the drought tolerance of cassava can effectively improve its yield. Long non-coding RNAs(lncRNAs) are present in a wide variety of eukaryotes. Recently, increasing evidence has shown that lncRNAs play a critical role in the responses to abiotic stresses. However, the function of cassava lncRNAs in the drought response remains largely unknown. In this study, we identified a novel lncRNA, DROUGHT-INDUCED INTERGENIC lncRNA(DIR). Gene expression analysis showed that DIR was significantly induced by drought stress treatment, but did not respond to abscisic acid(ABA) or jasmonic acid(JA) treatments. In addition, overexpression of the DIR gene enhanced proline accumulation and drought tolerance in transgenic cassava. RNA-seq analysis revealed that DIR preferentially affected drought-related genes that were linked to transcription and metabolism. Moreover, RNA pull-down mass spectrometry analysis showed that DIR interacted with 325 proteins. A protein–protein interaction(PPI)analysis found a marked enrichment in proteins associated with the mRNA export and protein quality control pathways.Collectively, these results suggest that DIR and its interacting proteins that regulate mRNA or protein metabolism are involved in mediating the drought stress response. Thus, regulating DIR expression has potential for improving cassava yield under drought conditions.

Effects of Seed Soaking with Paclobutrazol on Tillering and Physio-logical Characteristics of Sugarcane Seedlings

In order to study the effects of seed soaking with Paclobutrazol( PP333) on the tillering and physiological characteristics of sugarcane seedlings,sugar cane variety ROC22 was used as experimental material. The effects of seed soaking with different concentrations of PP333 were studied. The tiller number and growth of sugarcane were surveyed at the 6-leaf stage,the physiological indicators such as chlorophyll content,soluble protein content,proline content and peroxidase activity were measured at the 2-leaf,4-leaf,and 6-leaf stages. The results showed that the seed soaking with PP333 can effectively improve the tillering of sugarcane seedlings. The suitable concentration for the tillering of sugarcane and the growth and development of sugarcane was of 50 mg/L; the seed soaking with PP333 significantly increased the chlorophyll,soluble protein,proline,and peroxidase activity of leaves of sugarcane seedlings; the content of chlorophyll and soluble protein in leaves of sugarcane seedlings treated with 90 mg/L PP333 was the highest,and the proline content and peroxidase activity of sugarcane treated with 50 mg/L PP333 were the highest.

Effects of Application of Cassava Alcohol Anaerobic Fermentation Liquid and Mulching of Film on Overwintering and Next Year's Growth and Yield of Banana

The effects of application of cassava alcohol anaerobic fermentation liquid and mulching of film on overwintering and next year's growth and yield of banana were investigated in this study.The results showed that the application of cassava alcohol anaerobic fermentation liquid with COD concentration of 1 200-2 000 mg/L(900 m^3/hm^2) and mulching of film significantly increased the soil organic matter and available potassium contents in banana orchard,improved the cold resistance of banana seedlings,increased the pseudostem height,pseudostem circumference,green leaf number and chlorophyll content of next year's banana seedlings,brought the flower bud emergence period and harvest period forward,and significantly increased the yield per plant.

"Fenlong Law" and Its Scientific Significance

Based on application of " Fenlong tillage technology" in 40 kinds of crops in 26 provinces of China,and saline alkali land and degraded grassland of 10 provinces in the past 10 years, " Fenlong law" that Fenlong depth of various land resources suitable for cultivation in reasonable depth interval and utilization degree of " natural resources" are proportional to increase in agricultural output,ecological environment improvement and increase in economic output is discussed in this paper. Moreover,its formula,8 " effect laws" and their scientific significance are given. " Full-layer tillage" or " bottom-layer tillage" of Fenlong " super deep ploughing,deep loosening and not disturbing soil layer" is expounded,and the way of multiple incremental utilization of " natural resources" is created,which could be applied in various land resources suitable for cultivation,and realizes deep utilization of natural resources in a " big explosion". Additionally,China has 147 million ha of cultivated land,saline alkali land and degraded grassland,and 400 million people can be supported by the newly increased grain and meat,etc. by Fenlong,and 88 billion m^3 of land water resources is added. " Fenlong law" is proposed based on Fenlong phenomenon,and it is conducive to deep enjoyment and protection of natural resources by human beings,and harmonious development between man and nature.

Roles of Fenlong Technology in the Increase of Grain Yield and Construction of a Huge "Underground Reservoir"

Fenlong farming technology was introduced. It has characteristics of very deep tillage and evenly smashing soil,and can evenly smash soil without disturbing soil layers to complete the task of soil preparation. It can be widely used in cultivated land,saline-alkali land,lime concretion black soil,degraded grassland,etc. After the application of the technology in 34 crops in 24 provinces,it can increase yield by 10%-50% and improve quality by above 5%. Fenlong technology can increase soil reservoir capacity,enhance the infiltration rate of rainwater in soil and make " surplus" effect obvious. If the country plans and promotes the technology in 160 million hm^2 of land( including 67 million hm^2 of cultivated land,20 million hm^2 of saline-alkali land,6. 7 million hm^2 of marginal land and 67 million hm^2 of degraded grassland),the total volume of loosened soil in arable land will increase from 198. 1 billion to 840. 0 billion m^3,and the capacity of a " underground reservoir" will increase by 675 million m^3,while natural precipitation reserves will increase by 162 billion m^3. It can effectively solve food security problems and water resource problems such as drought,floods,and industrial,agricultural and domestic water shortages,as well as serious disaster hazards caused by groundwater that has been evacuated in China.

“Physical Fertility” of Fenlong and Its Yield and Benefit Increase

Core theory and acting force("physical fertility") of Fenlong are firstly proposed,and "physical fertility of Fenlong" is relative to the fertility of chemical fertilizer of increasing crop yield. Basic composition of "physical fertility of Fenlong" and its effect of increasing production and improving quality of various agricultural crops are clarified. It makes crop yield increase by 15%-30% without fertilization and 15%-50% by not increasing fertilization amount and irrigation water consumption. It is proposed that "physical fertility of Fenlong" could be sufficiently excavated in the new times of green development. Fenlong has a key significance for rationally reducing chemical fertilizer,soil,water and air pollution,agricultural cost,improving the quality of agricultural products and human health level.

Preliminary Explanation on "Natural Activation Theory" Based on "Fenlong"

Based on action mechanism of "Fenlong technology" with the maximum activation potential of global natural resources,"natural resources activation theory"("activation theory") is proposed firstly.Its connotation contains two parts.One is directly activating some natural resources in land,such as unutilized plough bottom of existing cultivated land and soil resources below it,saline-alkali land,degraded grassland,ecological reconstruction of desertification land,inter-row of fruit trees,lawn of sponge city,etc.The other is indirectly activating some natural resources in ground space,such as natural precipitation,solar energy,oxygen,terrestrial eco-environment,soil resources,river waters and even climate change factors.It could release and generate huge physical endogenous force and cyclic force,and increase food source and available water resources,which is favorable for human survival,nature's own ecological balance,harmonious coexistence and balance between man and nature,without harming nature itself.Moreover,its supporting theoretical system is explained from five aspects.It is pointed that the "activation theory" is deep derivation of "Fenlong technology" and "Fenlong science".By sufficiently playing the potential of natural resources,it could reach human-dominated comprehensive balance and coordinated development of air,sunshine,water,soil,nutrient,microorganism,plant,livestock and poultry,marine organism in the nature.The "activation theory" is concrete embodiment of respecting,changing and using the nature,and new channel of realizing sublimation of "life community of human and nature" and benefiting mankind.

Fenlong Tillage System by the Theory of “Natural Forces” and Possibility of “Fenlong Agriculture” Establishment

"Natural forces" ——core theory of Fenlong technique is explored in this paper. We break through key core technique of farming and agriculture,and invent new method of Fenlong tillage. Broad-spectrum Fenlong tillage technique system based on "full-layer and bottom-layer superdeep tillage without disturbance of soil layer" is established,which provides the possibility for establishing "modern Fenlong agriculture". When applied in 35 kinds of crops in 24 provinces of China,yield could be increased by 10%-50%,and even 1 times. In the transformation of severe saline-alkali land,corn yield could increase by 73. 0%,and Na,Cl and Mg ions in grain decrease by 20. 81%,1. 47%,and 9. 36% respectively. The newly developed "scarification tillage( reclamation) in the bottom area" could cover "bottom tillage" of dryland,paddy field,degraded grassland,perennial sugarcane,forest and fruit land,traditional Chinese medicine land,and ecological reconstruction of desertification land. It is point out that if Fenlong technique is used in 666 666. 67 km2 of farmland,200 000 km2 of saline-alkali land,666 666. 67 km2 of degraded grassland,and fisheries in rivers and offshore waters are used,trillion yuan of Fenlong economy could be formed,and the nationals will walk towards a healthier new era.Fenlong technique involves agriculture,forestry,water,grass,environment and other aspects,and its global promotion could improve eco-environment and change world development pattern.

Scientific Value of the Fenlong Tillage Erupting Super "Natural Forces" and Its Global Application

The concept of " natural forces" is proposed in farming field for the first time,and the core theory of Fenlong tillage is illustrated. This tillage method provides " super plough layer" and " super groundwater reservoir" by the machine,including six vertical spiral drills,can smash the soil vertically,without disorganizing soil layer. And this tillage method releases five " natural forces" with infinite space and time,including natural soil activation forces,natural fertility forces,natural water control forces,natural environment improvement forces,and natural river driving forces by activating various land resources. Fenlong tillage can significantly increase the source of high-quality food for human,and solve the problem of natural disasters by natural forces curing itself. It is proposed that the implementation of the " six key projects" by the " natural forces" of Fenlong tillage can solve the deep problems in China. The researchers suggest establishing Fenlong tillage great science engineering which could solve the problem of harmonious symbiosis between man and nature. The present results indicate that Fenlong tillage erupts super natural forces with infinite space and time,which can be used as a deep tillage practice to maintain the natural and environmental beauty of the earth forever.

Tillage Effect and Development Prospect of Fenlong Farming Tools with"Drill"

In this paper,farming and crop cultivation effects of farming tools with"drill"which are invented independently in China are clarified firstly,containing horizontal cutting of soil,super deep ploughing,deep loosening and not disturbing soil layer,granular soil,soil not easy to bond and harden,and one-time land preparation.It is a significant path to deeply develop and use the"five natural resources"not fully utilized by human beings(soil resources at plough bottom and below,saline-alkali land,natural rainfall,solar energy,oxygen)and realize"mitigation"of five natural disasters(flood,drought,high temperature,low temperature and climate warming).In the past 10 years,the farming tools have been applied in 40 kinds of crops in 26 provinces of China.Compared with vertical breaking of soil by traditional"plow",the amount of loose soil,water storage and dissolved oxygen in cultivated land increased by more than one time,and yield increased by 10%-50%.They have been applied in transformation of saline-alkali land in 10 provinces,and yield increased by 30%-150%.After Fenlong treatment for 1 and 2 years,biomass of sugarcane increased by 68.9%and 50.1%respectively.Net photosynthetic rates of Gramineous crops were improved by 6.82%-11.94%,while net photosynthetic rates of Legume crops were improved by 20.32%-32.08%.After"spiral drill","vertical two-knife drill","vertical three-knife drill"and other hollow series of Fenlong farming toolss were invented newly.They were the most advanced farming tools with large soil discharge and small resistance,and could be equipped in large-,medium-and small-size modern Fenlong agricultural machinery as key technology,thereby setting up a new"standard stalk"for world agricultural reform and bringing benefit to mankind.

Research on the Significance of Incremental Utilization of Natural Resources Based on "Fenlong Science of Natural Resources"

The basic principle of Fenlong technology is to make full use of the cultivated layer and the below soil resources and natural precipitation. It can increase the amount of loosen soil by 1-2 times, water and oxygen by 1 time, and available nutrients by 10%-30%, surface air humidity by more than 10%, crop net photosynthetic efficiency by 10%-30%, biomass by 20%-30%, crop yield by 10%-50%, and crop quality by 5%, and decrease salt content by 20%-40% and the emission of methane and other gases by 10%. In this study, it is firstly proposed to establish a new research field——"Fenlong science of natural resources"(referred to as "Fenlong science"), and the research contents include Fenlong-based sciences of modern agricultural machinery and equipment for full-layer ploughing and bottom ploughing, tillage, crop cultivation, utilization of water resources (natural precipitation, farmland water conservancy, groundwater resources, etc.), conversion and utilization of saline-alkali land, arable degraded grassland reconstruction, ecological reconstruction of desertification land, ecological environment, climate change, economic and social development. It clarifies theory and enriches technology, and provides a major platform for carrying global population developing from more than 7 billion to 10 billion and helping people and nature to mutually benefit.

Development of Molecular Marker Linked to Cf-10 Gene Using SSR and AFLP Method in Tomato

The leaf mould resistance gene Cf-10 on tomato confered resistant or immune to all prevalent physiological races of Cladosporium fulvum presented in three northeastern provinces of China in inoculation test. In order to better utilize Cf-10 gene in a marker-assisted selection program and to permit the pyramiding of one or several resistance genes in a cultivar, tightly linked SSR and AFLP markers were obtained by the bulked segregant analysis method. One SSR marker and three AFLP markers were identified linked to Cf-10 gene, with the distance of 9.73, 5.8, 8.5, and 10.6 cM, respectively. These markers will facilitate the selection of resistant tomato germplasm containing Cf-10 gene.