Chemical composition,energy and amino acid digestibility in double-low rapeseed meal fed to growing pigs

Background： The nutritional value of rapeseed meal may be variable due to the variation of its chemical composition. And a precise understandin9 of the nutritional value of an ingredient is beneficial for the accurate diet formulation and reduction of feed costs. This study was conducted to determine the chemical composition, dicjestible energy （DE） and metabolizable enercjy （ME） content, and apparent ileal digestibility （AID） and standardized ileal dicjestibility （SID） of amino acids （AA） for growincj pigs. Thirteen solvent-extracted double-low rapeseed meal （DLIRSM） samples were obtained from the main double-low rapeseed producing areas in China. Methods： The DE and ME contents of the 13 DLRSM samples were measured in cjrowin9 pigs （six pigs per DLRSM sample, average initial body weicjht （BW） =48.3 kg）. The AID and SID of AA of 10 DLRSM samples were determined in 12 crossbred barrows （average initial BW = 35.3 kcj） by using two 6 x 6 Latin square designs. Each Latin square comprised one N-flee diet and 5 DLRSM test diets. Results： The chemical composition of DLRSM varied among samples, and the coefficient of variation was greater than ]0 % for ether extract （EE）, neutral detergent fiber （NDF）, acid detergent fiber （ADF）, calcium （Ca）, and total 91ucosinolates. The AA content of DLRSM varied among samples especially for lysine （Lys） and methionine （Met）. On a dry matter （DM） basis, the apparent total tract digestibility （ATFD） of gross energy （GE）, the DE and ME and the ME：DE ratio of DLRSM averaged 62.39 %, 2862 kcal/k9 and 2723 kcal/kcj, and 94.95 %, respectively. The mean value of S1D of Lys was 70.52 % which varied from 66.54-76.54 %. The SID of crude protein （CP）, Met, and threonine （Thr） averaged 72.81%, 82.41%, and 69.76 %, respectively. Conclusions： There was great variability in chemical composition especially in the concentration of EE, NDF and ADF, but no significant differences in energy content of the DLIRSM samples were observed. In addition, the AID and SID of all AA were relatively similar amoncj DLRSM samples except for that of Lys.

Optimal Supplement Dosage of Double-Low Rapeseed Meal in Concentrated Feed of Fattening Lambs

[ Objective] To determine the optimal supplement dosage of double-low rapeseed meal in concentrated feed of fattening lambs. [ Method] A total of 120 Tibetan lambs at the age of 50 d were selected and divided randomly into four groups. The lambs in these four groups were fed with diets respectively supplemented the double-low rapeseed meal of 50,100,150 and 200 g/kg. Their diets had the same nutritional levels of energy and protein. The experimental period was 120 d. [ Result] Daily gain, feed conservation ratio and economic benefits were largely increased in the lambs fed with the diets supplemented the double-low rapeseed meal of 150 g/kg （Daily gain, P 〈 0.01 ）. However, the daily gain and feed conservation ratio were largely decreased in the lambs fed with the diets supplemented the double-low rapeseed meal of 200 g/kg. Moreover, serum levels of transaminase and thyroxine were not significantly different between the four groups. [ Conclusion] The optimal supplement dosage of the double-low rapeseed meal is 150 g/kg in fattening lambs.

Full Mechanized Production Technology for Double-Low Rapeseed in Xianning City

This paper standardizes the operation of rapeseed production including variety choosing,field preparation,mechanical seeding,field management,mechanical harvesting etc.,to realize full mechanization of rapeseed production. The key technologies: the optimum sowing date was from mid-September to mid-October in rapeseed-rice（corn） double cropping system region,and from mid-October to late October in rapeseed-rice-rice triple-cropping region; seeding rate was 4. 5 kg/ha-6. 0 kg/ha; the optimum density was 450000-750000 plants per ha;150-240 kg N fertilizer,60-90 kg P2O5 fertilizer,90-135 kg K2O fertilizer and 7. 5-15 kg B fertilizer were used per ha,50% of N fertilizer and the rest of fertilizer were used as basal fertilizer; segmented harvesting was done when 70%-80% of siliques per plant was yellow and combined harvesting was done when more than 90% of siliques per plant was yellow or brown.

SWOT Analysis of Industrial Development of Double-low Rapeseed in Hubei Province

Based on SWOT analysis method,this paper conducts analysis on the industrial development environment of double-low rapeseed in Hubei Province from the following four aspects,in order to crystallize its resources advantage and disadvantage and make it know the opportunities and challenges that it is faced by.First,advantage analysis:excellent geographic conditions,vigorous government support,powerful scientific research force,sound industrial system support;second,disadvantage analysis:poor quality,low-level fine and deep processing,scant publicity and promotion,lagged infrastructure conditions,shortage of effective market access mechanism and sound industry regulation,no brand effect;opportunity analysis:the opportunities brought by low-carbon economy,the opportunities brought by consumers' preference,the opportunities brought by policy environment,the opportunities brought by establishment of strategic union;threat analysis:fierce external competition,continuous decline of comparative benefit.The results of research show that in order to promote industrial development of double-low rapeseed in Hubei Province,we should implement brand effect strategy,quality management strategy and strategy of deepening industrial system,give full play to existing geographic advantage and other advantages,grasp scarce opportunities and actively confront challenges.

Analysis of Correlation between Yield and Quality Traits of Quality Hybrid Rapeseed

[Objective] This study aimed to investigate the correlation between yield and quality traits of rape. [Method] Taking ＂Sanbei 98＂ and ＂Youyan 599＂ as ex- periment materials, correlation between yield and quality traits of Brassica napus L. cultivars was explored by orthogonal rotation method. [Result] The results showed that： 1 In both the two varieties-Sanbei98 and Youyan599, erucic acid content had the largest coefficient of variation, but its average content was lower than 2% in both the two varieties （0.90% in Sanbei98 and 1.24% in Youyan599）, and the palmitic acid content had the smallest coefficient of variation. 2 In terms of the dif- ferences in quality traits at different yield levels, only the mean of eicosenoic acid content revealed significant difference in Sanbei98, and only the mean of seed-pro- tein content revealed significant difference in Youyan599, and there was no signifi- cant difference in any combined quality traits in both the two varieties. 3 The yield was negatively correlated with the erucic acid content or oil content, and posi- tively correlated with the content of seed-protein, linoleic acid, or linolenic acid, and the coefficient of correlation between the yield and either of the contents of glucosi- nolates, oleic acid, palmitic acid, stearic acid, and eicosenoic acid was smaller. ~, when the yield of a variety increased considerably, there was a certain decreasing trend in erucic acid content, oil content, the total amount of erucic chain fatty acids （El ＆ Er）, while there was an increasing trend in seed-protein content, linoleic acid content, linolenic acid content, saturated fatty acids （SFA）, the total amount of fat and protein （P ＆ F）, unsaturation index （IUFA）, unsaturated fatty acids （UFA）, the total amount of 18 carbon fatty acids （18-C FA）, unsaturated fatty acids [UFA/（Ei ＆ Er） ], and the sum of oleic acid and linoleic acid （OI ＆ Li）. 5 When the seed-pro- tein content is increased, the quality of rape oil cake is also improved; when the unsaturated index is increased, the oil stability is decreased. The increase in the total amount of unsaturated fatty acids, oleic acid and linoleic acid helps to increase in the total amount of fatty acids absorbed by human bodies. [Conclusion] This study provides a theoretical foundation for the cultivation of high-yielding and top- quality hybrid rape cultivars.

De novo design of future rapeseed crops:Challenges and opportunities

To address the global demand for rapeseed while considering farmers’profit,we face the challenges of making a quantum leap in seed yield and,at the same time,reducing yield loss due to biotic and abiotic stresses.We also face the challenge of efficiently applying new transformative biotechnology tools such as gene editing and breeding by genome design to increase rapeseed productivity and profitability.In this Perspective,we review advances in research on the physiological and genetic bases of both stress factorsaffected yield stability and seed yield potential,focusing on source–sink relationships and allocation of photosynthetic assimilates to vegetative growth and seed development.We propose research directions and highlight the role of plant architecture in the relative contributions of the root system,leaves,and pods to seed yield.We call for de novo design of new rapeseed crops.We review trait variation in existing germplasm and biotechnologies available for crop design.Finally,we discuss opportunities to apply fundamental knowledge and key germplasm to rapeseed production and propose an ideotype for de novo design of future rapeseed cultivars.

National Protection Zone for Rapeseed Production and Industrial Cluster of Rape in Hubei Province

Hubei Province is the main winter rapeseed producing area in China,and has the national advantage and characteristic industrial cluster of rape.The protection zone for the production of important agricultural products of rapeseed in Hubei Province also ranks first as that in Hunan Province.This paper studied the winter rape industry,the important agricultural product production protection zone of rapeseed,the provincial double-low high-quality rape protection zone and the industrial cluster of rape in Jianghan Plain in Hubei Province,and analyzed the main problems existing in the development of rapeseed production protection zone and industrial cluster of rape.Finally,it came up with strategies including promoting national rape varieties,overcoming the problem of rape"agricultural chip",promoting the"rice+rape"rotation model,and strengthening the protection of intellectual property rights of brand marks.

Effects of harvesting method and date on yield loss and seed quality of rapeseed

China is one of the major rapeseed production countries in the world,but harvesting mechanization was still backward,and high harvest loss was a key inhibiting factor for rapeseed production.To obtain optimum harvesting date for winter rape in the Yangtze River Valley of China,artificial simulated combine harvesting and artificial two-stage harvesting were adopted to find correlations between harvesting date,rape variety,seed oil content,protein content,grain moisture rate,rapeseed straw moisture content,rapeseed unthreshing rate,grain drop loss rate,thousand seeds weight(TSW),and harvesting economic coefficient(HEC).Analysis of variance showed that rapeseed oil content,protein content and TSW were correlated with rape variety;HEC was correlated with harvesting method and rape variety.Rape variety was the dominant factor of rapeseed oil content,protein content,TSW and HEC.Grain moisture rate,un-threshing rate,grain drop loss rate and straw moisture content were correlated with harvesting method and date.Harvesting date was the dominant factor of rapeseed moisture rate,un-threshing rate,grain drop loss rate and straw moisture rate.Single factor tests further proved that harvesting date had less impact on rapeseed oil content,protein content,TSW and HEC.It showed little correlation with rapeseed quality except grain moisture rate.The optimum harvesting date could be known by change in straw moisture content.The combined harvesting should be carried out during the grain moisture content of 15%-20%with TSW stabilized in the highest level.The twostage harvesting cutting should be carried out at the grain moisture content of 35%-40%.This research offered a reference to harvesting method and date for rape cultivated in the Yangtze River Valley.

Host-induced silencing of MpPar6 confers Myzus persicae resistance in transgenic rape plants

Plant-mediated RNA interference(RNAi)has emerged as a promising technology for insect control.The green peach aphid,Myzus persicae,feeds on over 400 species of host plants.Brassica napus(rape)is the second most important oilseed crop worldwide.Myzus persicae is highly reproductive and causes severe damage to the rape plants due to its quite flexible life cycle.In this study,we tested the RNAi effects of transgenic rape plants on M.persicae.By in vitro feeding M.persicae with artificial diets containing double-stranded RNAs(dsRNAs)targeting seven aphid genes,we identified a new gene encoding the partitioning-defective protein 6(Par6)as the most potent RNAi target.Tissue-and stage-expression analysis of Par6 suggested this gene is highly expressed in the embryo and adult stage of M.persicae.We next generated transgenic rape plants expressing ds Par6 by Agrobacteriummediated transformation and obtained nine independent transgenic lines.Compared to wild-type control plants,transgenic rape lines expressing ds Par6 showed strong resistance to M.persicae.Feeding assays revealed that feeding transgenic rape plants to M.persicae significantly decreased MpPar6 expression and survival rate and impaired fecundity.Furthermore,we showed that the resistance levels to M.persicae are positively correlated with ds Par6 expression levels in transgenic rape plants.Our study demonstrates that transgenic rape plants expressing ds Par6 are efficiently protected from M.persicae.Interfering with the genes involved in embryo development could be the effective RNAi targets for controlling aphids and potentially other insect pests.

Regulatory mechanisms of rapeseed petal color formation:Current research status and future perspectives

Flower color,an important rapeseed character,has great practical value and research significance.It has become an area of intensive research in recent years.This paper summarizes the latest research progress on rape flower color in terms of variety,source,pigment composition,formation mechanism,and omics.Moreover,it provides an overview of rape flower color breeding and omics.

Influence of Nostoc entophytum and Tetracystis sp. on Winter Survival of Rapeseed

Bioassay results proved that several microalgae strains of the Mosonmagyaróvár Algal Culture Collection (MACC) enhanced plant growth, due to their hormone content and other secondary metabolites. The aim of the current research was to improve autumn growth and winter survival of rapeseed (Brassica napus L.) by treatment with two microalgae strains selected by bioassay results. Experimental plots were set up in Mosonmagyaróvár in 2010 and 2013. Winter rapeseed hybrid (B. napus L. cv. Orlando) plants were treated in 4-6 leaves stage with 0.3 g/L and 1 g/L suspensions of MACC-612 Nostoc entophytum Bornet & Flahault and MACC-430 Tetracystis sp. in middle of October. After the treatments, the following parameters were recorded: chlorophyll-a and b, carotenoid, dry matter content of leaves, average amount of autumn foliage, diameter of root collar, length of shoot tips, fresh and dry weight of root, and number of plants in autumn and spring. Both microalgae treatments significantly increased pigment concentration and dry matter content of leaves, number of fully grown leaves (13%-46%) and dry root weight (16%-36%). Treatments with 0.3 g/L and 1 g/L MACC-612 suspensions increased the length of shoot apices by 14%-18% and 25%-35%, respectively. Number of overwintered control plants decreased significantly in both years (31%), but there was no decrease in parcels treated with 1 g/L of MACC-612 and MACC-430. Microalgae treatments could increase plant growth and survival, which contributed to the significant increase of thousand seed weight (18%-25%) and total yield (by 10%-24%).

SPAD chorophyll meter was suitable in nitrogen quick diagnosis,yield forecast and fertilization recommendation in rapeseed(Brassica napus L. )

Nitrogen （N） is one of the most important nutrients for oilseed rape （Brassica napus L . ） , but there is a lack of quick diagnosis and recommended fertilization. Three field experiments were con-ducted to seek the best diagnostic method and establish a fertilizer rate recommendation model. For ex-periment 1, six treatments as application N 0,90,180,240,300 and 400kg ha -1 were designed, and the general N nutrition diagnosis method as SPAD -502 chlorophyll meter, RQflex plus 10 nitrate reflectrom- eter and GreenSeeker - 505 spectrometer were used at eight leaf stage, tenth leaf stage and bolting stage of rape to determine the suitable nitrogen rapid diagnosis method and establish the model of yield forecast and N rate recommendation as topdressing. The experiment 2 was designed to validate the veracity of yield forecast model obtained from experiment 1. The experiment 3 was designed to test the accuracy of N rate recommendation model come from experiment 1. The results indicated that there is a preferable inter-relation between N application rates and rape yield for experiment 1 （ y = - 0. 0176x2 ＋ 11. 136x ＋797. 88 ,R2 =0. 9905 ＊ ＊ ） , which conform to the performance of yield variation with N application levels as shortage, appropriate and excessive rapeseed. For three diagnosis methods, nitrate reflectrometer could reflect rape N nutrition status to some extent, but which influenced by rapeseed physiological char-acteristics such as lower biomass at seedling stage and luxury absorption of N at bolting stage, and the re-liability and stability of diagnosis were inferior. Spectrometer is suitable for quick N nutrition diagnosis at bolting stage, but the stage of topdressing is too late to meet the demand of N support. SPAD meter could more suitable in quick N diagnosis of oilseed rapes since it could reflect rape N nutrition preferable, and it has some advantages such as the strong stability, easy measuring and lower cost in detection. By SPAD meter, model of yield forecast yforeCastyield =370. 517xSPAD value -13310.3 （x 〈42. 54） and recommended N rate yR_dedNrate =162.7-[（370.517xSPADTflliie- 13 10. 3 ）/10. 0617 - 76. 7398 ] （x〈42.54） were established. For experiment 2, the actual yield and forecast yield showed good correlation （y = 0. 5022 ＋2244. 3x, R2 =0. 7852 ＊ ） . For experiment 3 , the amount of topdressing N calculate from recommended N rate model were put forward, and the yield for different treatments had no significant difference. Total-ly ,SPAD chlorophyll meter could be used in quick N nutrition diagnosis, forecast yield and N recommen-dation of oilseed rape.

Indoor Propagation of Transgenic Glyphosate-tolerant Rapeseed (Brassica napus L.) and Transfer Breeding for Herbicide Tolerance

[Objectives] This study was conducted to investigate the possibility of screening for herbicide resistance in the early stage of rapes growth. [Methods] Eight treatments were set for a herbicide concentration experiment. [Results] Rape sprouts were highly sensitive to the herbicide glyphosate, and even a very low concentration of glyphosate solution(187 mg/L) was sufficient to kill most of the rape seedlings, while the genetically modified herbicide-tolerant rape could tolerate higher concentrations of the herbicide. Low concentrations of glyphosate could be used for screening at the sprout stage, and the results of herbicide-tolerance screening were consistent with PCR testing. [Conclusions] This study lays a technical and material foundation for accelerating the cultivation of new herbicide-resistant rape varieties suitable for rapeseed production areas in the lower reaches of the Yangtze River.

Strategies and Economic Benefit Analysis for Productive Landscape of Rape Flower Sea in Cold Regions

The cold regions are located in high latitudes and cold climates.The local excellent ornamental plant resources are relatively scarce.The plant species that are suitable for both ornamental and productive benefits of landscape of flower sea construction are also even fewer.Therefore,it is imperative to introduce and screen the plant resources suitable for cold regions to create the landscape of flower sea.The rape,an oilseed crop,was used as a research object in order to create a productive flower landscape with both ornamental and economic values in cold regions.Four rape flower varieties,Qingza No.5,7,9,and 11,were introduced from Qinghai Hufeng Agricultural Science and Technology Group Co.,Ltd.They were planted in the experimental practice base of Northeast Agricultural University in three batches.Development characteristics and seed yield of rape flowers on different sowing dates were studied.The fuzzy probability method was used to comprehensively evaluate the varieties.The results showed that the rape flowers grew well in Harbin City during the experimental sowing period,which could form a good landscape of flower sea and had a considerable rapeseed yield.It could be widely used in cold urban and rural areas,such as Harbin City.In view of the experimental results,the strategies of creating a productive landscape of rape flower sea were proposed and the economic benefits were analyzed.It could change the status quo of a uniform landscape of flower sea in cold regions,help the development of rural tourism,and promote local economic income.

Different Foliar Fertilizer Treatments Affect the Yield and Quality of Brassica napus L.for Both Vegetable and Oil Dual-Use Rape

Field experiments were carried out to study the effect of different foliar fertilizer treatments on the agronomic traits,yield,and quality of Brassica napus L.for both vegetable and oil dual-use rape.The seedlings of‘Youtai 929’,‘Jinyoutai 1’,and‘Zhongshuang 11’were sprayed with potassium dihydrogen phosphate,naphthylacetic acid,and selenium fertilizer,and the agronomic traits,yield,and quality were determined.The results showed that the naphthylacetic acid treatment had the highest indexes before winter,followed by the selenium fertilizer treatment.At the harvesting stage,the plant height,number of siliquae,yield per plant,and number of effective branches on the main stem of the three varieties were the highest in the naphthylacetic acid treatment,followed by those in the potassium dihydrogen phosphate treatment.The fresh shoot quality was the best in the selenium fertilizer treatment and the second in the naphthylacetic acid treatment.‘Jinyoutai 1’applied with naphthylacetic acid had the highest economic benefit of 4971.78 CNY/667m^(2),which was 642.32 CNY/667m^(2) higher than that of the control.The findings suggested that naphthylacetic acid was suitable to be used as the foliar fertilizer for the seedlings of B.napus varieties for both vegetable and oilseed,and the additional application of selenium fertilizer demonstrated better effect.

Genome-wide and candidate gene association studies identify BnPAP17 as conferring the utilization of organic phosphorus in oilseed rape

Phosphorus(P)is essential for living plants,and P deficiency is one of the key factors limiting the yield in rapeseed production worldwide.As the most important organ for plants,root morphology traits(RMTs)play a key role in P absorption.To investigate the genetic variability of RMT under low P availability,we dissected the genetic structure of RMTs by genome-wide association studies(GWAS),linkage mapping and candidate gene association studies(CGAS).A total of 52 suggestive loci were associated with RMTs under P stress conditions in 405 oilseed rape accessions.The purple acid phosphatase gene BnPAP17 was found to control the lateral root number(LRN)and root dry weight(RDW)under low P stress.The expression of BnPAP17 was increased in shoot tissue in P-efficient cultivars compared to root tissue and P-inefficient cultivars in response to low P stress.Moreover,the haplotype of BnPAP17^(Hap3)was detected for the selective breeding of P efficiency in oilseed rape.Over-expression of the BnPAP17^(Hap3)could promote the shoot and root growth with enhanced tolerance to low P stress and organic phosphorus(Po)utilization in oilseed rape.Collectively,these findings increase our understanding of the mechanisms underlying BnPAP17-mediated low P stress tolerance in oilseed rape.

Nutrient and growth elucidation of a novel coated urea on oilseed rape in three main cultivation areas

A novel coated urea(MVCU)was prepared,and its application effect was verified by field trials of oilseed rape in three main cultivation areas.Meanwhile,the nutrient release and coating layer changes of MVCU in static water at 25C and different soils were systematically evaluated.MVCU showed a long nutrient release time under static water(77 days)and soil incubation(140 days)conditions due to the slow degradation of the coating layer in MVCU,and its nitrogen release coincided well with oilseed rape nitrogen demand.The above results were further confirmed by FT-IR spectra and SEM analysis.Compared with conventional urea(U),the field trials of MVCU in the three main cultivation areas showed high nitrogen utilization efficiency and yield advantages in oilseed rape.The field trials results indicated that the MVCU significantly enhanced the aboveground dry matter(28.7%),the seed nitrogen concentration(9.5%)and aboveground nitrogen accumulation(42.5%)of oilseed rape at the mature stage as compared to that of the U.The oilseed rape yield enhanced by 932.8 kg/hm^(2),the average growth rate was 65.1%,and nitrogen utilization efficiency increased by 21.2%.In short,MVCU has the advantages of excellent slow-release performance and strong applicability,and its yield-increasing effect on oilseed rape could reach or even be better than that of traditional fertilization.

Effects of Nitrogen Application Rate, Density and Seedling Age on Dry Matter Accumulation of No-tillage Rape in Seedling Stage

[Objective] The aim of the research was to find the optimal nitrogen application rate, density and seedling age for no-tillage rape in seedling stage. [Method] With the D-optimal quadratic regression design for three factors, the 310 scheme was designed to study the effects of nitrogen application rate, density and seedling age on dry matter accumulation of no-tillage rape in seedling stage. [Result] With the increase of nitrogen application rate, density and seedling age, the dry matter content appeared like a parabola, increasing firstly and then declining. The change of nitrogen application rate caused greater influence than that of density and seedling age; the interaction effects between nitrogen application rate and density were greater than that between nitrogen application rate and seedling age as well as between density and seedling age. [Conclusion] Considered comprehensively, the dry matter content of no-tillage rape in seedling stage reached the highest level (4 768.2 kg/hm2) when the nitrogen application rate, the density and the seedling age were 195 kg/hm2, 93 000 plants/hm2 and 33 d, respectively.

Chloroplast Composition and Structural Differences in a Chlorophyll-reduced Mutant of Oilseed Rape Seedlings

对黄化突变体Cr352 9和野生型油菜 (BrassicanapusL .) 352 9叶绿体的超微结构和组成进行了比较。与野生型相比 ,突变体Cr352 9叶片具有较少的类囊体、较少的垛叠膜区和较少的叶绿素含量。突变体的Chla/Chlb比值较高 ,是野生型的 2倍。电泳结果表明 ,突变体类囊体膜中LHCⅡ和其三聚体LHCⅡ 的含量减少。SDS_PAGE分析显示 ,LHCⅡ的脱辅基蛋白在突变体类囊体膜中明显减少。免疫印迹进一步表明 ,所有LHCⅡ组分的含量仅为野生油菜的类囊体膜的 1 / 3。突变体Cr352 9的天线系统比野生型 352 9的小。

Biomechanical Characteristics of Rape Stalks

[Objective] To study the correlation between the biomechanical properties of rape stalks and rape stem lodging. [Method] Through axial compression tests to the stalks of 4 different rape varieties, the change rules of maximum stem bearing ca- pacity, maximum compressive strength, elastic modulus and moment of inertia along plant height were analyzed, as well as the effect of different varieties and water contents on the biomechanical property indices of rape stalks. [Result] The maximum loads of rape stalks presented liner decrease trend along with the increase of stem height, and all reached the maximums below the height of 50 cm. The maximum stem compressive strength and elastic modulus of the 4 varieties were increased with ascending height, but in a slow rate with small change, thus the modulus of e- lasticity could be considered as unchanged. The maximum bearing capacity, maxi- mum compressive strength and elastic modulus of dry rape stalks were higher than wet stalks, indicating that the water contents of rape stalks had significant effect on their mechanical properties. According to the actual lodging situations in filed, stalks of variety No. 1 owned the worst biomechanical properties and lodging degree, while the biomechanical properties of No. 6 and F5 were better than No. 1 and No. 9, and they also had stronger lodging-resistance. [Conclusion] The study provides parameters and bases for the design of mechanized production and mechanical deep processing of crops, and can better reveal the physical natures of organisms. The methods used in this study can also be used to screen excellent crop stalks.