Lodging is more than just plants falling over;it incurs significant economic losses for farmers leading to a decrease in both yield and quality of the final produce.Human management practices,such as dense sowing,excessive nitrogen fertilizer applications,inappropriate sowing dates,and upland rice cultivation,exacerbate the risk of lodging in rice.While breeders have developed high-yielding rice varieties utilizing the sd1 gene,relying solely on this gene is insufficient to enhance lodging resistance.Identifying the traits that contribute to lodging resistance is crucial.Key factors include biochemical,anatomical,and morphological traits,such as the levels of lignin,cellulose,hemicellulose,silicon,and potassium,along with the number and area of vascular bundles and the thickness,diameter,and length of the culm.Moreover,markers associated with lodging-related genes,like SCM2,SCM3,SCM4,and prl4,can be utilized effectively in marker-assisted backcrossing to develop rice varieties with desirable culm traits.This literature review aims to aid rice breeders in addressing the issue of lodging by examining traits that influence lodging resistance,developing phenotyping strategies for these traits,identifying suitable instrumentation,exploring methods for screening lodging-resistant plants,understanding the mathematical relationships involved,and considering molecular breeding aspects for pyramiding genes related to lodging.
Crops are prone to lodging with the decline of stem moisture and the intervention of other factors in the mature harvest period,such as garlic,which is difficult to harvest mechanically.To solve this problem,the plant-correcting reel for harvesting lodging garlic plants,bumped and deformed with plants many times to pull and lift them into a conveyor,is proposed in this study.We analyzed the motion trajectory equation and key influencing factors of the reel and defined the lifting and plant-correcting stages as three processes of contact,stirring and release.For example,the contact deformation model and system energy equations were established in the contact process.Besides,in the stirring process,the garlic plant-correcting conditions were established through the dynamic simulation test analysis of garlic seedling trajectories and the deflection model of garlic stem was constructed.Furthermore,in the release process,the expressions of rubber bars rotation and garlic plant offset bending curvature were constructed and the optimal number and distribution form of bars were determined.Meanwhile,the mechanism and key operating parameters of the auxiliary lifting mechanism of the divider were established.Through the single-factor test,the influence of reel speed,forward speed and reel height on the success feeding rate was analyzed under different bars distribution forms;Through multi-factor experiments,the interaction contour map of various factors was constructed.When reel speed,forward speed and reel height were 3 rad/s,3.5 m/s,and 540 mm,the feeding success rate was 98.73%.The optimization factors were tested and verified,which met the operational requirements of a high feeding success rate and low loss rate of garlic harvest.This study combines laboratory virtual as well as field experiments and analyzes of trajectory of bars,contact deformation and deflection model of garlic plant,and reel rotation and garlic plant offset bending curvature to solve the problem of garlic lodging mechanized harvest and yield reduct
Rice lodging,a phenomenon precipitated by environmental factors or crop characteristics,presents a substantial challenge in agricultural production,notably impacting yield prediction and disaster assessment.Despite that the application of conventional methodologies like visual assessment,mathematical models,and satellite remote sensing technologies has been employed in the segmentation of crop lodging,these approaches are still constrained in precision,immediacy,and capacity for large-scale evaluation.
Panli ZhangLonghui NiuMengchen CaiHongxu ChenXiaobo Sun
Direct-seeding rapeseed production at high plant density raises the risk of lodging.We investigated the use of dwarf genes to improve rapeseed plant architecture to balance yield and lodging.Three genotypes with different plant architectures(dwarf sca^(HS5),semi-dwarf+/sca^(HS5),and tall ^(HS5))were evaluated under varying nitrogen rates(N1,N2,and N3:120,240,and 360 kg N ha^(-1))and plant densities(D1,D2,and D3:15,45,and 75 plants m^(-2))from 2019 to 2022.The results showed that increasing N rate positively influenced yield while decreasing lodging resistance in all genotypes.Increasing plant density(D2-D3)enhanced lodging resistance and yield in sca^(HS5) and+/sca^(HS5),but reduced yield in ^(HS5).Compared to the two parents,+/sca^(HS5) exhibited moderate expressions of IAA3,GH3.15,and SAUR30 in stems under N2D3,resulting in reduced plant height and increased compactness.Additionally,+/sca^(HS5) had a thicker silique layer than ^(HS5) by 14.7%,and it had a significant correlation between branch height/angle and yield.Increasing N rate led to increased lignin and pectin contents,while cellulose content decreased.Increasing plant density resulted in greater stem cellulose content and CSLA3/7 expression in sca^(HS5) and+/sca^(HS5),but decreased in ^(HS5).Compared to ^(HS5),+/sca^(HS5) exhibited higher expressions of ARAD1 and GAUT4,along with a 51.1%increase in pectin content,leading to improved lodging resistance under N2D3.Consequently,+/sca^(HS5) showed a 46.4%higher yield and 38.9%lodging resistance than ^(HS5) under N2D3,while sca^(HS5) demonstrated strong lodging resistance but lower yield potential.Overall,this study underscores the potential of utilizing auxin dwarf genes to optimize the trade-off between yield and lodging resistance in rapeseed and the possibility of maximizing yield potential by optimizing the plant architecture of+/sca^(HS5) through nitrogen reduction and dense planting.
Lodging is still the key factor that limits continuous increases in wheat yields today,because the mechanical strength of culms is reduced due to low-light stress in populations under high-yield cultivation.The mechanical properties of the culm are mainly determined by lignin,which is affected by the light environment.However,little is known about whether the light environment can be sufficiently improved by changing the population distribution to inhibit culm lodging.Therefore,in this study,we used the wheat cultivar“Xinong 979”to establish a low-density homogeneous distribution treatment(LD),high-density homogeneous distribution treatment(HD),and high-density heterogeneous distribution treatment(HD-h)to study the regulatory effects and mechanism responsible for differences in the lodging resistance of wheat culms under different population distributions.Compared with LD,HD significantly reduced the light transmittance in the middle and basal layers of the canopy,the net photosynthetic rate in the middle and lower leaves of plants,the accumulation of lignin in the culm,and the breaking resistance of the culm,and thus the lodging index values increased significantly,with lodging rates of 67.5%in 2020–2021 and 59.3%in 2021–2022.Under HD-h,the light transmittance and other indicators in the middle and basal canopy layers were significantly higher than those under HD,and the lodging index decreased to the point that no lodging occurred.Compared with LD,the activities of phenylalanine ammonia-Lyase(PAL),4-coumarate:coenzyme A ligase(4CL),catechol-O-methyltransferase(COMT),and cinnamyl-alcohol dehydrogenase(CAD)in the lignin synthesis pathway were significantly reduced in the culms under HD during the critical period for culm formation,and the relative expression levels of TaPAL,Ta4CL,TaCOMT,and TaCAD were significantly downregulated.However,the activities of lignin synthesis-related enzymes and their gene expression levels were significantly increased under HD-h compared with HD.A partial least squares path m
Yibo HuFeng QinZhen WuXiaoqin WangXiaolong RenZhikuan JiaZhenlin WangXiaoguang ChenTie Cai
