Agronomic cultivation measures on productivity of oilseed flax:A review

Oilseed flax is one of the most important oil crops in China.With the improvement of people's living standards and the deepening knowledge of the nutritional value of oilseed flax,the demand and economic value of oilseed flax are increasing,and the cultivated area in China is expanding.However,the grain yield of oilseed flax is lower than other oil crops.It varies significantly from year to year,combined with a lower degree of mechanization,which has greatly limited the healthy development of the flax industry.Some of the effects of agronomic measures on productivity and water use efficiency of oilseed flax are reviewed in this paper.The major agronomic strategies for the productivity of oilseed flax were presented based on fertilization,plant density,irrigation,cropping pattern and weed control.Future research should investigate the effect of silicon and potassium fertilizers on the mechanism of lodging resistance of oilseed flax,the effects of diversified cropping systems(strip intercropping and crop rotation)on high and stable productivity and efficient utilization of resources.

The integrated risk assessment and zoning of meteorological disaster in Heilongjiang Province of China

This paper describes studies on the integrated risk assessment and zoning of meteorological disaster in Heilongjiang Province,in northeastern China,by using information-diffusion theory and cluster method with 35 years of summer temperature and precipitation data from 74 meteorological stations from 1971 through 2005.The information-diffusion theory has been used extensively in risk assessment,yet almost no one has done research about risk assessment by information-diffusion theory based on meteorological disaster standards.Some research results are as follows:the risk probability of low temperature and cold damage in the northern region is higher than that in the southern region;the risk probability of general low temperature and cold damage in the southwestern region is the highest;the risk probability of serious low temperature and cold damage in the northern region is the highest,followed by the central and southeast region;the high-risk region of arid disaster in Heilongjiang Province was primarily located in the southwestern,central,and southern parts of the province;the high-intensity arid disaster was located in the south-eastern region;the high-risk region of flood in Heilongjiang Province was primarily located from the southwest and then across the central part to the western part of Heilongjiang Province;the high-intensity flood disasters were located in almost every part of Heilongjiang Province.We can conclude from the integrated meteorological disaster risk zoning that the high-risk region of mete-orological disaster is primarily located in the southern and northern part of the province,the moderate-risk region is distributed in the central southern region and western region,the low-risk region is located in the eastern part,and the light-risk region is located in the central western part of Heilongjiang Province.

Perspective on oil flax yield and dry biomass with reduced nitrogen supply

Field experiment was arranged in a randomized complete block design to determine effects of nitrogen(N)application levels(J0:150 kg/hm^2,J1:120 kg/hm^2,J2:90 kg/hm^2,J3:60 kg/hm^2)on regulating dry biomass accumulation,allocation and translocation,and grain yield of oil flax during 2018 cropping season.Significant promotion was observed in dry matter during accumulation stage of oil flax,when N rate was reduced by 40%(from 150 to 90 kg/hm^2).Under J2 treatment,translocation of dry matter from vegetative organs to pod increased by 38.46%and 61.54%respectively,when compared with J1 and J0 treatment Dry matter distribution proportion of pod at maturity increased 4.47%-7.61%,contribution rate of leaf to grain upgraded 5.09%-8.77%,and number of effective pods and grains per pod increased by 27.16%-45.38%and 6.49%-26.59%respectively compared to other treatments.As a result,seed yield of oil flax under J2 treatment was 2.23%-18.21%higher than those of other treatments.Our study recommended 90 kg/hm^2 as the best N fertilizer level to improve seed yield of oil flax.

Effect of different film color mulching on dry matter and grain yield of oil flax in dry-land

Mulching can effectively maintain soil moisture;color of mulching film affects soil water storage capacity and further promote crop growth to improve grain yield.Field experiment was conducted to study effects of different film colors on dry matter accumulation(DMA)and grain yield of oil flax.Results showed that white plastic film mulching could increase leaf area,chlorophyll content and DMA.DMA of white film mulching and micro-ridge with soil covering was 53.0%higher than that of CK,and 7.8%higher than that of black film mulching.Mulching method also influenced DMA.Micro-ridge alone increased it by 13.7%than flat cultivation and soil covering improved another 7.6%under white film mulching.Both white and black film mulching with microridge could significantly improve grain yield.Black film mulching with micro-ridge and soil covering,white film mulching with micro-ridge and no soil covering significantly increased capsule number per plant,1,000-grain weight and grain yield of oil flax,compared with CK.Grain yield increased 29.0%and 28.9%respectively.These results indicated that the above mulching methods were suitable for high yield cropping pattern in dry-farming regions.

Varied previous crops on improving oilseed flax productivity in semiarid Loess Plateau in China

To investigate the effects of crop rotation on oilseed flax growth and yield,three season experiments were carried out in semi-arid area of Dingxi,Gansu from 2017 to 2019.The designed 6 rotational systems were FFF(flax-flaxflax),PFF(potato-flax-flax),WPF(wheat-potato-flax),FPF(flax-potato-flax),PWF(potato-wheat-flax)and FWF(flax-wheat-flax).Flax growth and yield investigation results showed that crop rotation increased leaf area duration,dry matter accumulation,seed nitrogen accumulation,water and nitrogen used efficiency,compared with continuous cropping of flax.Flaxseed yields in rotation systems were 22.23%–44.11%greater than those of continuous cropping system.Those in wheat and potato stubbles had higher tiller number(21.43%and 29.46%),more branches(14.24%and 6.97%),effective capsules(26.35%and 28.79%),higher water use efficiency(40.26%and 33.5%),higher nitrogen partial factor productivity(33.85%and 31.46%)and dry matter(41.98%and 25.47%)than those in oilseed flax stubble.It concluded that crop rotation system was an effective measure for oilseed flax productivity in semi-arid area by improving yield components and promoting biomass.

Oilseed flax(Linum usitatissimum L.),an emerging functional cash crop of China

Oilseed flax(Linum usitatissimum L.)is one of the most important oil crops in alpine regions of North and Northwest China,which is an annual herb and belongs to Linaceae family and Linum genus.According to the application,Linum is often divided into three types,production oil,extraction fiber and both for production oil and extraction fiber.Oilseed flax is native to Near East and Mediterranean coasts.It is widely distributed throughout the world,with the largest cultivated area in Asia and Europe,followed by the Americas.Canada is the largest area for planting oilseed flax and China is second.In China.

Film mulching treatment inf luences dry matter and yield of oil flax in semi-arid area of China

A feld study was set up to compare dry matter accumulation and grain yield of 3 different types of flm mulching, namely FFC （full flm muched on tiny ridges covered with soil）, PFC （full flm muched covered with soil）, and PF （full flm muched with no cover）. The experiment was laid out in a complete random design with 3 replications at north-west （34°40′N, 105°06′E） of China. This study determined that （1） flm mulching treatment increased leaf area and dry matter accumulation of oil fax in semi-arid areas; （2） accu-mulation of dry matter under PFC treatment was markedly higher than other treatments except anthesis stage; （3） average grain yield of oil fax under flm mulching treatment was 52.67%-60.33% higher than fat plot without mulched or ridge （CK） treatment; （4） grain yield of oil fax was substantially correlated with plant height, grain number and 1,000 kernels weight. This study demonstrated that flm mulching has signifcant effects on crop grain yield improvement in the northwest of China.

Effects of bone morphogenetic protein-4 on spatial memory and cholinergic expression in the dentate gyrus after fornix-fimbria transection in rats

BACKGROUND： Previous experiments have confirmed bone morphogenetic proteins （BMPs） upregulate cholinergic expression in neurons isolated from the embryonic rat hippocampus and cerebral cortex. Therefore, BMPs could be useful for treating Alzheimer＇s disease and other neurodegenerative diseases. OBJECTIVE： BMP-4 was infused into the hippocampal dentate gyrus of fomix-fimbria transected rats to test the effects of BMP-4 on cholinergic expression in dentate gyrus neurons, and to observe changes in spatial memory behavior. DESIGN： A randomized controlled animal experiment. SETTING： Department of Neurosurgery and Laboratory for Cell Biology, Institute of Geriatrics, General Hospital of Chinese PLA. MATERIALS： Twenty-seven healthy adult male Sprague Dawley （SD） rats, weighing 250-300 g, were provided by the Laboratory Animal Center of the General Hospital of Chinese PLA. Reagents： BMP-4 （B-2680, Sigma Company） and choline acetyl transferase （CHAT） antibody （AB5042, Chemicon Company） were used in this study. Equipments： a rat stereotaxic instrument （type： SN-2N, Narushige Group, Japan） and Image-prog-plus image analysis software （Media Cybernetics company, USA） were used in this study. The protocol was carried out in accordance with ethical guidelines for the use and care of animals. METHODS： This experiment was performed in the Institute of Geriatrics, General Hospital of Chinese PLA between July 2004 and March 2005. Rats were randomly divided into 4 groups： Alzheimer＇s disease group （n = 7）, normal control group （n = 5）, BMP-4-Alzheimer＇s disease group （n = 8）, and model group （n = 7）. In the Alzheimer＇s disease group, the left hippocampal fomix-fimbria of rats was transected to mimic Alzheimer＇s disease symptoms. In the BMP-4-Alzheimer＇s disease group, 1 μt L BMP-4 （10 mg/L） was perfused into the left dentate gyrus with a microinjector at 1 μ L/min. In the model group, 1 μ L saline was perfused into the same position by the same method. Twenty-eight days after injection, Morris water maze test was performed in all rats to test spatial memory. Time-to-platform and swim-path length were recorded. Immunohistochemical staining of cholinergic neurons was performed on brain sections containing dentate gyrus. The area covered by ChAT-positive cells was analyzed using an Image-prog-plus image analysis software. MAIN OUTCOME MEASURES： Area covered by ChAT-positive cells in the dentate gyrus. Time-to-platform and swim path-length. RESULTS： Twenty-seven rats were included in the final analysis. In the Alzheimer＇s disease group, the area covered by ChAT-positive cells was significantly smaller compared with the normal control group （F = 76.03, P 〈 0.01）. The area covered by ChAT-positive cells was significantly larger in the BMP-4- Alzheimer＇s disease group than in the model group （F = 35.17, P 〈 0.05）, but significantly smaller than in the normal control group （F = 40.17, P 〈 0.05）. Time-to-platform and swim-path length were significantly longer in the Alzheimer＇s disease group than in the normal control group （F =24.62 and 631.58, respectively, both P 〈 0.05）. Time-to-platform and swim-path length were significantly shorter in the BMP4-Alzheimer＇s disease group compared with the model group （F= 22.06 and 606.89, respectively P 〈 0.05）. CONCLUSION： Injection of BMP-4 into the dentate gyrus of Alzheimer＇s disease model rats alleviates central cholinergic system injury and concomitantly improves spatial memory.

Effect of nitrogen and phosphorus application on soil nitrogen morphological characteristics and grain yield of oil flax

In order to identify effects of nitrogen(N)and phosphorus(P)on soil nitrogen morphological characteristics and grain yield of oil flax,a two-factor experiment was conducted in a randomized complete block design in typical semi-arid and hilly-gully area of Loess Plateau with 3 replicates in 2013 and 2014.Two levels of N application included 150 kg/hm2(N2)and 75 kg/hm2(N1).P application included 150 kg P2 O5/hm2(P2)and 75 kg P2 O5/hm2(P1).Temporal and spatial variation of soil nitrate nitrogen(NO3-N)and ammonium nitrogen(NH4+-N)contents in 0-60 cm soil layer,and relationship between soil NO3-N accumulation(SNA)and grain yield of oil flax were analyzed.Results showed that SNA increased with evaluated N application rate in different soil layers(0-20 cm,20-40 cm and 40-60 cm).With the increased P application,SNA increased at N1 level but decreased at N2 level.SNA under N2 P1 treatment increased by 73.33%in 2013 and 74.97%in 2014 respectively,compared with control treatment(CK)at maturity stage.Grain yield of oil flax also increased by 44.27%in 2013 and56.55%in 2014,compared with CK under the same treatment.Correlation analysis showed that SNA in different soil layers were respectively positively correlated with grain yield.In conclusion,this research suggested that the optimal fertilizer application rate was 150 kg N/hm2 and 75 kg P2 O5/hm2 in the Northwest of China.

Engineer and split an efficient hypercompact CRISPR–CasΦ genome editor in plants

The programmable CRISPR-Cas genome editing technology,adopted from prokaryotic adaptive immune systems,has revolutionized genome engineering in plants(Liu et al.,2022a).Many efforts have been made to improve the activity,specificity,and protospacer adjacent motif(PAM)variants of Class 2 Cas nucleases,such as Cas9,Cas12a,and Cas12b(Liu et al.,2022a).However,their large size(∼1000–1400 amino acids)poses a challenge in scenarios requiring a compact Cas nuclease,particularly in urgent situations like plant virus-induced genome editing(Cheuk and Houde,2018;Li et al.,2021;Varanda et al.,2021).