Gene expression profiles in early leaf of rice(Oryza sativa)and foxtail millet(Setaria italica)

Plant anatomy is patterned early during leaf development which suggests studying the spatial–temporal transcriptomes of primordia will help identify critical regulative and functional genes.We successfully isolated the leaf primordia tissues from the C3grass rice and the C4grass foxtail millet by laser capture microdissection(LCM)and studied the gene expression throughout leaf developmental stages.Our data analysis uncovered the conserved expression patterns of certain gene clusters both in rice and foxtail millet during leaf development.We revealed genes and transcription factors involved in vein formation,stomatal development,and suberin accumulation.We identified 79 candidate genes associated with functional regulation of C4anatomy formation.Screening phenotype of the candidate genes revealed that knock-out of a putative polar auxin transport related gene NAL1 resulted significantly reduced veinal space in rice leaf.Our present work provides a foundation for future analyses of genes with novel functions in grasses and their role in leaf development,in particular the role in leaves with a contrasting C3vs.C4biosynthetic pathway.

Hydrothermal treatment of pearl millet grains:Effects on nutritional composition,antinutrients and flour properties

Pearl millet(Pennisetum glaucum)is one of the major millets with high nutritional properties.This crop exhibits exceptional resilience to drought and high temperatures.However,the processing of pearl millet poses a significant challenge due to its high lipid content,enzyme activity,and presence of antinutrients.Consequently,it becomes imperative to enhance the quality and prolong the shelf life of pearl millet flour by employing suitable technologies.Hydrothermal treatment in the food industry has long been seen as promising due to its potential to reduce microbial load,inactivate enzymes,and improve nutrient retention.This study aims to investigate the effects of hydrothermal treatment on the quality characteristics of pearl millet.The independent variables of the study were soaking temperature(35,45,55℃),soaking time(2,3,4 h),and steaming time(5,10,15 min).Treatment conditions had a statistically significant effect on nutrient retention.Major antinutrients like tannins and phytates were reduced by 0.99% to 5.94% and 0.36% to 6.00%,respectively,after the treatment.Lipase activity decreased significantly up to 10% with the treatment conditions.The findings of this study could potentially encourage the use of pearl millet flour in the production of various food items and promote the application of hydrothermal treatment in the field of food processing.

Study of the Constraints of Millet Production (Pennisetum glaucum (L.) R. Br.) and the Peasant Perception of Biological Control in the Tahoua Region

Millet (Pennisetum glaucum (L.) R. Br.) is the Sahelian crop par excellence due to its adaptation to the particular production conditions in this region. Unfortunately, in recent years this crop has been threatened by very strong parasitic pressure and drought during the production period. The objective of this study is to analyze the main constraints of millet production and the solutions known to producers. A survey was carried out in November 2022 with a sample of 298 producers in five municipalities in the Tahoua region. The main constraints are drought and pressure from crop pests (locust, millet ear miner, floricultural insects) according to 57.9% of respondents. The millet ear miner is the most formidable pest according to 55% of respondents. Thus, the average yield obtained in a year of good production without the leafminer is 194 kg/ha and that obtained in a year of millet ear leafminer is around 27 kg to 43 kg/ha depending on the municipality. The yield obtained this last campaign after the attack of this leafminer varies from 64 to 77 kg/ha depending on the municipalities compared to a potential yield of over 1000 kg/ha. More than half of producers (58.1%) are unaware of the existence of biological control compared to only 12.5% who are aware of this alternative method. Work to popularize this technology is necessary in the five municipalities and the entire region in general.

Technological advancements in millet dehulling and polishing process: An insight into pretreatment methods, machineries and impact on nutritional quality

Millets are widely recognized for their nutritional significance;however, the methods employed for their processing are currently lacking. This article primarily focuses on the advanced technologies and progressions in millet dehulling and polishing. These technologies operate based on the fundamental principles of compression-shearing, abrasion-friction, and centrifugal-impact forces. Processing of millets can be challenging because of the physical characteristics and tight attachment of hull and bran to the endosperm. However, several dehullers have been designed to solve this problem for different kinds of millets. In addition, the nutritional and anti-nutritional characteristics undergo alterations due to both dehulling and polishing processes. These alterations are thoroughly examined and discussed in this article. Specifically, anti-nutrients such as tannins and phytate are predominantly found in the outer pericarp of the grain and experience a reduction after undergoing dehulling and polishing. The nutritional properties are also subjected to a reduction;however, this reduction can be mitigated by subjecting the grains to certain pretreatments before dehulling and polishing. These treatments serve to enhance dehulling efficiency and nutrient digestibility while simultaneously reducing the presence of anti-nutrients. Novel thermal and non-thermal methodologies such as microwave, hydrothermal, high-pressure processing, and ohmic heating can be employed for processing millets, thereby diminishing the loss of nutrients. Additional research can be carried out to investigate their impact on the dehulling and polishing of millets.

Gut microbiota remodeling drived by dietary millet protein prevents the metabolic syndrome

Metabolic syndrome(Met S)is a chronic disease associated with the disturbance of gut microbiota homeostasis.Metabolites derived from gut microbes play essential roles in Met S prevention and therapy.Here,we focused on the inhibitory effect of the extract of millet bran protein(EMBP)on a high-fat diet(HFD)-induced Met S,aiming to identify gut microbiota and their metabolites that involve in the anti-Met S activity of EMBP.The obesity,chronic inflammation,insulin resistance in Met S mouse models were abolished after EMBP treatment.The protective mechanism of EMBP against HFD-induced Met S may depend on improved gut barrier function.Using microbiome analysis,we found that EMBP supplementation improved gut microbiome dysbiosis in Met S mice,specifically upregulating Bacteroides acidifaciens.The fecal microbiota transplantation(FMT)also demonstrated this phenomenon.In addition,metabolomic analysis showed that EMBP mediates metabolic profiling reprogramming in Met S mice.Notably,a microbiota-derived metabolite,gamma-aminobutyric acid(GABA),is enriched by EMBP.In addition,exogenous GABA treatment produced a similar protective effect to EMBP by improving NRF2-dependent gut barrier function to protect HFDinduced Met S.The results suggest that EMBP suppress host Met S by remodeling of gut microbiota as an effective candidate for next-generation medicine food dual purpose dietary supplement to intervene in MetS.

SiRAP2-12,a Positive Regulatory Factor,Effectively Improves the Waterlogging Tolerance of Foxtail Millet(Setaria italica)

Foxtail millet(Setaria italica)growth was inhibited because of waterlogging stress,which has caused yield reduc-tion.ERF family plays an important role to plant adversity tolerance.In our study,we obtained 19,819 differential expressed genes(DEGs)between the two treatments based on the RNA-seq sequencing of foxtail millet of water-logging stress.Furthermore,a total of 28 ERF family members were obtained,which have a complete open read-ing frame.We studied the evolution and function of SiERF family and how they affected the waterlogging tolerance.It was found that SiERF1A/B/C(GenBank ID:OR775217,OR775219,OR775218)and SiRAP2-12(GenBank ID:OR775216)have similar functions to the known waterlogging tolerance genes of other plants.Among them,the SiRAP2-12 expression was obviously significantly up-regulated in foxtail millet after 5d water-logging stress.After SiRAP2-12 was silenced,the activity of defense enzymes in millet decreased significantly.In details,superoxide dismutase(SOD),catalase(CAT)and peroxidase(POD),the osmotic regulator proline(Pro),and the activity of the anaerobic respiratory enzyme alcohol dehydrogenase(ADH)content were decreased by 78.61%,29.52%,79.95%,19.41%and 54.77%,respectively.In contrast,the relative electrical conductivity contents(REC),malondialdehyde(MDA),and hydrogen peroxide(H_(2)O_(2))of the foxtail millet subjected to virus-induced gene silencing clearly increased by 1.03-fold,36.09%,and 15.21%,respectively.The content of sodium(Na^(+))in the SiRAP2-12-silenced foxtail millet also increased,but that of potassium(K^(+))decreased.Interestingly,we found that ethylene content was significantly reduced.Further,the SiAOC1 expression,an essential gene for ethylene synthesis,was inhibited in SiRAP2-12-silenced foxtail millet after waterlogging stress.Taken together,we hypothesized that SiRAP2-12 might be a positive regulator of millet tolerance to waterlogging stress.

Effects of Seeding Date and Density on Yield and Agronomic Traits of Millet : A Case Study of Wangu 098 Variety of Millet

[Objectives]To find out a suitable cultivation technique of Wangu 098 in Nanyang area,speed up the popularization,demonstration and application of Wangu 098,and provide a theoretical and practical basis for adjusting the planting structure and realizing the matching of improved varieties and methods.[Methods]The new self-bred millet variety Wangu 098 was used as the material,and the two-factor split zone experimental design was adopted.The effects of different sowing dates and densities on the yield,growth period and agronomic characters of millet were studied.[Results]The interaction of seeding date and density had a great effect on the yield and plant traits of millet.Millet yield was significantly and positively correlated with plant height,panicle length,single panicle weight,panicle grain weight and tiller number.[Conclusions]The reasonable combination of seeding date and density could give full play to the yield potential of millet.According to the experimental results and cultivation experience,the suitable seeding date of millet in Nanyang area is in the first and middle ten days of June,and the best density is about 750000 plants/ha.However,after June 30,the seeding millet did not tiller,so the density should be increased to more than 900000 plants/ha to obtain higher yield.In terms of cultivation and management,timely seeding,reasonable close planting,and coordination of vegetative growth and reproductive growth can make the plant tall and strong,panicle long and thick,and improve the yield of millet.

Millet Origin Identification Model Based on Near-infrared Spectroscopy

[Objectives]This study was conducted to clarify the difference of millet from different producing areas in near-infrared spectroscopy(NIRS)modeling.[Methods]Millet samples from six different regions were collected for NIRS analysis,and an origin identification model based on BP neural network was established.The competitive adaptive reweighted sampling(CARS)algorithm was used to extract characteristic wavelength variables,and a CARS-BP model was established on this basis.Finally,the CARS-BP model was compared with support vector machine(SVM),partial least squares discriminant analysis(PLS)and KNN models.[Results]The characteristic wavelengths were extracted by CARS,and the number of variables was reduced from 1845 to 130.The discrimination accuracy of the CARS-BP model for the samples from six producing areas reached 98.1%,which was better than SVM,PSL and KNN models.[Conclusions]NIRS can quickly and accurately identify the origin of millet,providing a new method and way for the origin identification and quality evaluation of millet.

Performance Evaluation of Novel Eco-Materials Composed of Millet Husks, Rice Husks, and Polystyrene

Managing agricultural waste and expanded polystyrene (EPS) poses significant environmental and economic challenges. This study aims to create composites from millet husks, rice husks, and recycled EPS, using a manufacturing method that involves dissolving the polystyrene in a solvent followed by cold pressing. Various particle sizes and two binder dosages were investigated to assess their influence on the physico-mechanical properties of the composites. The mechanical properties obtained range from 2.54 to 4.47 MPa for the Modulus of Rupture (MOR) and from 686 to 1400 MPa for the Modulus of Elasticity in Bending (MOE). The results indicate that these composites have potential for applications in the construction sector, particularly for wood structures and interior decoration. Moreover, surface treatments could enhance their durability and mechanical properties. This research contributes to the valorization of agricultural and plastic waste as eco-friendly and economical construction materials.

Evaluation of Phytochemical Analysis and Total Phenol Content of Proso Millet and Barnyard Millet

Whole grains of proso and barnyard millets were sequentially extracted using different solvents(hexane,chloroform,ethyl acetate,and methanol).Phytochemical analysis was performed qualitatively,and the total phenolic content in the extracts of proso and barnyard millets was quantified.Alkaloids and cardiac glycosides were identified in all solvent extracts of both millets.Anthraquinone and glycosides yielded negative results in all solvent extracts of both millets.Among all the solvent extracts,methanol extracts of proso and barnyard millets showed the presence of major compounds such as flavonoids,terpenoids,amino acids,tannins,and phenolics compounds.The maximum amount of phenols was found in methanolic extracts of proso and barnyard millets(0.669±0.003 and 0.625±0.003),followed by the chloroform extract of proso and barnyard millets(0.284±0.002 and 0.257±0.003).The minimum amount of phenolics was found in the acetone extract of proso and barnyard millets.The methanol extract of both millets showed the presence of major compounds with high phenolic content.

Considerations for gluten free foods-pearl and finger millet processing and market demand

The market demand for gluten free foods is increasing due to frequent incidences of celiac disease and increasing awareness on consumption of gluten free foods.Millets have become the major constituent of diet as they are gluten-free and also excellent sources of micro and macro nutrients such as vitamins,minerals,dietary fibers and phenolic compounds.Among various millets,the finger millet and the pearl millet are the two most important and common millet varieties grown extensively.Since,they are regarded as the staple foods of the poor and vulnerable populations,development of new products and improvements in their nutritional quality will aid in the general health of these population.Processing of millets and production of variable gluten-free ready-to-eat and nutritional supplements has increased their market value in the recent years.Furthermore,processing can also help in shelf-life extension of the millets with nutritional enrichment,expanding its markets to non-traditional millet consumers.In this context,the present review is aimed to focus on the current processing methods to develop products from the two millet varieties that are gluten free and outline their nutritional benefits.

Millet/peanut intercropping at a moderate N rate increases crop productivity and N use efficiency,as well as economic benefits,under rain-fed conditions

Cereal and legume intercropping has been widely adopted to increase crop productivity in sustainable farming systems worldwide.Among different intercropping combinations,millet and peanut intercropping can be adapted to most waterlimited areas.However,there are few studies on the differences in yield characteristics and nitrogen use efficiency between millet/peanut intercropping and monocultures under different nitrogen (N) application rates.The objective of this study was to determine the yield advantages and economic benefits,as well as the appropriate N application rate,of millet/peanut intercropping.A two-yearfield experiment was conducted with three cropping patterns (monoculture millet,monoculture peanut and millet/peanut intercropping) and four N rates (0,75,150 and 225 kg ha^(-1)).The results showed that the land equivalent ratio (LER) and net effect (NE) of the intercropping system reached their highest levels at the N input of 150 kg ha^(-1)in 2018 and 2019 (1.04 for LER,0.347 Mg ha^(-1)for NE,averaged across two years).Millet was the dominant crop in the intercropping system (aggressivity of millet and peanut (Amp)>0,competitive ratio of millet and peanut (CRmp)>1),and millet yields achieved their highest values at N inputs of 225 kg ha^(-1)for monoculture and 150 kg ha^(-1)for intercropping.NUE reached its highest levels with N inputs of 150 kg ha^(-1)for all planting patterns over the two years.Intercropping combined with an N input of 150 kg ha^(-1)achieved the highest net income of 2 791 USD ha^(-1),with a benefit-cost ratio of 1.56,averaged over the two years.From the perspective of economics and agricultural sustainable development,millet/peanut intercropping at 150 kg N ha^(-1)seems to be a promising alternative to millet or peanut monoculture.

Nutritional Composition and Anti-Nutrient Levels in Raw and Processed Varieties of Finger Millet Promoted for Nutritional Security

Finger millet (FM) is rich in nutrients such as minerals, vitamins, and amino acids. However, the levels of nutrients and their bioaccessibility depend on the variety, the levels of ant nutrients, the chemical form of nutrients, and the type of processing methods used. The study determined the levels of selected nutrients, anti-nutrients, and bioaccessibility in raw and processed varieties of finger millet being developed by the Kenya Agricultural and Livestock Research Organization (KALRO) in Kenya. Raw finger millet seeds from KALRO Centers in Kenya were processed by malting for 60 hours and roasting at 110°C for 5 minutes as the optimal conditions. Levels of minerals were determined by AAS and AES, anti-nutrients by UV-visible spectrophotometer, proteins by the Pierce kit method, and vitamins by HPLC. The IE4115 and IE3779 showed the highest levels of nutrients and lowest levels of antinutrients hence preferred for processing and bioaccessibility studies. The level (mg/100 g) of selected minerals;K, Cr3+, Mg, Ca, P, Fe, and Zn were found to be highest in the following varieties of the FM;IE3779 (688.519 ± 1.57), IE 4115 (1.29 ± 0.07), IE4115 (294.38 ± 1.93), IE3779 (466.67 ± 4.17), IE4115 (250.92 ± 0.33), KERICHO P (16.98 ± 0.05) and IE4115 (64.10 ± 2.35) respectively. For β-carotene, vitamin B, B2, B3, B6 and B9 the levels were highest in the following varieties of FM;KAKW3 (0.023 ± 0.02), IE4115 (14.85 ± 0.16), IE4115 (12.998 ± 0.04), IE4115 (5.843 ± 0.07), IE3779 (0.06 ± 0.04) and KAKW4 (9.832 ± 0.08). Phytates, tannins, phenols, and oxalates were found to be lowest in the following varieties: IE3779 (14.20 ± 2.90, IE4115 (27.83 ± 0.73), NKFM1 (9.69 ± 0.07) and IE4115 (0.25 ± 0.01). The highest bioaccessibility values reported for K, Mg, Ca, P, Cr3+, Fe, and Zn were 89.53% (malting, IE3779), 49.28% (malting, IE4115), 60.41% (Malting, IE4115), 69.40% (malting, IE4115), 12.9% (malting, IE4115), 59.84% (malting, KAKW3) and 66.89% (roasting, IE3779) respectively (Table 8). For beta carotene, vitamin B1, B2, B3, B6 and B9 the values were 73.33% (malting, p224), 78.84% (malting, IE4115), 78.34 (malting, IE3779), 97.63% (malting, IE4115), 91.64% (malting, IE4115), and 77.52% (roasting, IE4115) (table The result on levels and bioaccessibility showed that IE4115 and IE3779 varieties were more nutritious and therefore should be promoted for nutritional security.

Salt stress responses in foxtail millet:Physiological and molecular regulation

Foxtail millet(Setaria italica L.),a member of the Paniceae family,is a temperate and tropical grass species that is widely cultivated on the Eurasian continent.It is Chinese in origin and possesses a small genome,short growth cycle,and strong natural abiotic stress resistance.Elucidating the mechanism of millet tolerance to salt stress is becoming increasingly important with increasing soil salinization limiting crop productivity.The responses and mechanisms of tolerance to salt stress from other model plants such as Arabidopsis and rice,were compared with those from foxtail millet to summarize current research on responses to salt stress.Numerous processes are involved in these processes,including physiological reactions,sensing,signaling,and control at the transcriptional,post-transcriptional,and epigenetic levels.To increase crop productivity and agricultural sustainability,a variety of technologies can be used to investigate how salt tolerance is mediated by physiological and molecular processes in foxtail millet.

Integrated genomic and transcriptomic analysis reveals genes associated with plant height of foxtail millet

Foxtail millet(Setaria italica)is an important C4 model crop;however,due to its high-density planting and high stature,lodging at the filling stage resulted in a serious reduction in yield and quality.Therefore,it is imperative to identify and deploy the genes controlling foxtail millet plant height.In this study,we used a semi-dwarf line 263A and an elite high-stalk breeding variety,Chuang 29 to construct an F2 population to identify dwarf genes.We performed transcriptome analysis(RNA-seq)using internode tissues sampled at three jointing stages of 263A and Chuang 29,as well as bulk segregant analysis(BSA)on their F2 population.A total of 8918 differentially expressed genes(DEGs)were obtained from RNA-seq analysis,and GO analysis showed that DEGs were enriched in functions such as‘‘gibberellin metabolic process”and‘‘oxidoreductase activity”,which have previously been shown to be associated with plant height.A total 593 mutated genes were screened by BSA-seq method.One hundred and seventy-six out of the 593 mutated genes showed differential expression levels between the two parental lines,and seven genes not only showed differential expression in two or three internode tissues but also showed high genomic variation in coding regions,which indicated they play a crucial role in plant height determination.Among them,we found a gibberellin biosynthesis related GA20 oxidase gene(Seita.5G404900),which had a single-base at the third exon,leading to the frameshift mutation at 263A.Cleaved amplified polymorphic sequence assay and association analysis proved the single-base in Seita.5G404900 co-segregated with dwarf phenotype in two independent F2 populations planted in entirely different environments.Taken together,the candidate genes identified in this study will help to elucidate the genetic basis of foxtail millet plant height,and the molecular marker will be useful for marker-assisted dwarf breeding.

谷子中矮秆资源创制、遗传解析和育种利用

谷子是旱作生态农业的主栽作物和应对气候变化的战略储备作物,也是新时期功能基因研究的模式作物。谷子品种的中矮秆化是产业发展的必然趋势。国内外目前已报道的谷子矮秆材料达70多个,从形态上谷子矮秆种质可以分为叶穗直立的紧凑型和叶穗下披的常规型2类;赤霉素(GA)敏感性测定发现4个材料对GA不敏感,其他均是GA敏感型;显隐性分析表明,多数矮秆材料为隐性单基因控制,但矮88株高为多基因控制。利用自然群体关联分析和双亲杂交分离群体合计发掘了109个控制株高的QTL,精细定位了7个矮秆基因,半显性矮秆材料84133的矮化基因SiDW1是唯一克隆并进行功能分析的矮化基因。对谷子中矮秆品种选育的梳理表明,利用矮88和其衍生系为亲本已培育出139个中矮品种(系),实现了谷子株高的显著矮化,满足了机械化收获对抗倒伏降株高的要求。本文综述了国内外谷子株高矮化基因的研究进展,梳理了已经定位和克隆的谷子矮秆基因,讨论了谷子矮秆遗传和育种研究中的问题,展望了未来发展方向。

干旱及复水对谷子苗期根系形态特征及叶片解剖结构的影响

本试验选用抗旱性强的谷子品种济谷16和旱敏感谷子品种鲁谷1号为材料,设置盆栽试验,于出苗15 d时停止浇水进行干旱胁迫处理,并于9 d后复水,研究不同抗旱性谷子品种叶片以及根系形态指标对干旱-复水的响应。结果表明:(1)与CK相比,干旱胁迫导致两个谷子品种的根分枝数、根尖数和根体积显著减少;复水后,济谷16的根尖数显著增加(P<0.05),而鲁谷1号的根尖数进一步显著降低。济谷16的根分枝数在复水后的增加幅度大于鲁谷1号。(2)干旱胁迫下,两个品种叶片泡状细胞面积缩小,叶片厚度下降;复水后济谷16泡状细胞面积与CK相当,而鲁谷1号仍显著小于CK(P<0.05)。(3)干旱胁迫下济谷16下表皮气孔密度增加,上表皮气孔密度减小,且均与CK差异显著(P<0.05);复水后,上表皮气孔密度略有增加但仍低于CK,下表皮气孔密度降低至CK水平。干旱胁迫下鲁谷1号上、下表皮气孔密度较CK均显著下降(P<0.05);复水后,上表皮气孔密度继续降低,而下表皮气孔密度显著增加至略高于CK水平。干旱胁迫后济谷16上、下表皮气孔长度无显著变化,复水后较CK和干旱处理均显著增加;鲁谷1号上表皮气孔长度显著减小(P<0.05),复水后仍继续减小,但较干旱处理差异不显著;鲁谷1号下表皮气孔长度较CK增加但差异不显著,复水后继续增长,显著高于CK。综上所述,干旱胁迫后复水,抗旱品种济谷16通过根分枝数和根尖数的增加以及叶片泡状细胞面积、气孔密度快速恢复,使其表现出更强的形态适应性和自我调节能力。

氮肥施用对谷子产量及小米米色的影响

为探究不同氮肥施用量对谷子产量及小米米色的影响,以优质谷子龙谷25为试验材料,采用随机区组设计,设置0(CK)、75(T1)、150(T2)、225(T3)、300(T4)、450(T5)kg/hm^(2)6个氮肥施用量处理,测定谷子关键生长时期生物量、养分积累量,成熟期产量相关性状,收获后磨米进行米色测定。结果表明,谷子拔节期植株生物量随施氮量的增多而增加;抽穗期、灌浆期、成熟期植株生物量随施氮量的增多表现为先增加后降低的趋势,在氮肥施用量为300 kg/hm^(2)时达到最大。谷子各生育期植株养分积累量随施氮量的增多大体呈现先增加后降低的趋势;植株全氮积累量在施氮量为150~225 kg/hm^(2)时较大,全磷积累量在施氮量为150 kg/hm^(2)时达到最大,全钾积累量在施氮量为300 kg/hm^(2)时达到最大。施肥条件下的产量及产量相关性状均高于不施肥,且在施氮量为300 kg/hm^(2)时产量最高。各氮肥处理下的小米表面色度L^(*)、a^(*)、b^(*)值均无显著差异;施氮量为225 kg/hm^(2)时L^(*)值最大,小米色泽更亮;氮肥施用量为75 kg/hm^(2)时b^(*)值最大,小米更黄,过量施用氮肥不利于小米黄色素的形成。综上,氮肥施用量为150~300 kg/hm^(2)有利于兼顾谷子高产和优质,可结合市场需求调整施肥量,以平衡产量和品质的关系。

糜子种质资源淀粉含量与Waxy基因等位变异分析

本研究测定了100份糜子种质资源的直链淀粉和支链淀粉含量,采用分子标记对胚乳直链淀粉合成调控基因Waxy进行基因分型,并选取不同直链淀粉含量代表种质资源进行基因测序和差异位点分析。结果表明,100份糜子种质资源直链淀粉含量变化幅度为0~22.78%,平均6.07%,直链淀粉含量低于3.7%的糯性材料占36%,完全糯性材料占24%;支链淀粉含量变化幅度为4.55%~56.73%,平均15.30%。分子标记M5/R11扩增产物能有效区分S_(0)、S_(-15)和S_(0)S_(-15)基因型;标记int5Lf/R3和M12/R12的PCR产物利用内切酶ACC I和Eco N I剪切,可鉴别出L_(C)、L_(Y)、L_(F)基因型。100份糜子种质共发现9种基因型,其中S_(0)/L_(c)数量最多,占33%,S_(-15)/L_(F)占25%,杂合型S_(0)S_(-15)/L_(F)、S_(0)S_(-15)/L_(C)、S_(0)S_(-15)/L_(Y)L_(F)各占2%。通过Waxy基因序列比对,在地方品种甘谷黑蝉背、黑糜子、庆阳饿死牛,育成品种晋黍9号、赤糜2号等种质资源中发现了大量新的SNPs位点,可用于基因功能和糜子育种材料创制研究。本研究结果为糜子分子育种工作及品质改良提供了理论依据。

谷子籽粒类黄酮含量和粒色的QTL定位

谷子(Setaria italica L.)是我国北方地区重要的粮食作物,籽粒营养丰富,且富含多种类黄酮物质,对生长发育和品质形成发挥着重要作用。目前谷子籽粒类黄酮合成及粒色形成相关调控机制研究较少。分析谷子类黄酮含量及粒色性状相关的QTL,为类黄酮合成关键基因的精细定位、克隆及功能研究奠定基础,同时,也为揭示谷子类黄酮合成及代谢机制和培育富含类黄酮谷子品种提供技术支撑。本研究以红粒色高类黄酮品种金苗红酒谷和黄粒色低类黄酮品种豫谷28为亲本构建的包含150个家系的重组自交系(RIL)群体为试验材料,在谷子成熟期对籽粒粒色和类黄酮含量相关性状进行分析。同时,采用复合区间作图法(composite interval mapping,CIM)对粒色和类黄酮含量进行QTL定位与分析,并对QTL置信区间内的候选基因进行预测。相关性分析表明,类黄酮含量与粒色呈显著正相关。共定位到4个与类黄酮含量相关和11个与粒色相关的QTL,分别位于1号、2号、5号、6号、7号、8号和9号染色体上,单个QTL的表型贡献率为2.01%~29.25%,6个为主效QTL,其中,qSC1-2和qFLA1-1、qSC7-1和qFLA7-1、qSC9-3和qFLA9-1为2个性状下共同定位到的QTL。通过基因预测与功能注释,筛选出QTL置信区间内5个与类黄酮物质合成及代谢相关的候选基因,表明类黄酮物质的合成、代谢及利用相关基因极有可能控制了这些基因的表达。15个QTL分别聚集于7条染色体上,基于基因功能注释,共筛选了5个与谷子类黄酮合成及代谢相关的候选基因,表明不同QTL位点参与到了共同遗传机制,并可通过分子标记辅助选择进行类黄酮合成及代谢等有利基因的聚合育种。