高粱[Sorghum bicolor(L.)Moench.]叶面积校正值(K 值)的初步研究

通过对两个高粱品种叶面积校正值(K 值)的初步研究,提出了在高粱叶面积测算中采用叶面积校正值K=0.72的建议,并对K 值在应用中的可靠性进行了分析。

高粱黄色籽粒基因Yellow Seed 2的定位及候选基因分析

高粱在我国农业结构调整和酿酒行业中具有重要的作用。籽粒颜色是高粱重要的性状之一,但有关高粱籽粒颜色的研究并不多。本研究观察了高粱黄色籽粒材料GLB41的籽粒发育过程,花后1~16 d为快速生长期,17~24 d进入缓慢膨大期,第25天开始进入转色期,绿色逐渐褪去,籽粒颜色由乳白色或苍白色逐渐变成浅黄色,随后颜色加深,40 d后籽粒颜色变为深黄色。利用黄色籽粒GLB41和白色籽粒6E16两个材料构建的群体,使用重测序BSA方法,将控制黄色籽粒性状的基因初定位在1号染色体15.6 Mb区间内,利用3215株分离个体将该基因定位在BR13和P2两个标记之间,区间内有7个候选基因,对这些基因的功能注释进行分析并测序,结果表明GLB41、6E16两个材料中未被报道过的基因Yellow Seed 2(Sobic.001G397900)的编码区内第619~621位插入CTG 3个碱基,导致增加了1个Leu(亮氨酸),第819位C突变为G,导致Cys(半胱氨酸)突变为Trp(色氨酸);第912位C突变为T,但氨基酸序列无变化。因此推测Yellow Seed 2可能参与这两份亲本材料籽粒颜色的形成。本研究为高粱籽粒颜色性状的研究提供了新的基因。

Characterization of subunits encoded by Sn RK1 and dissection of combinations among these subunits in sorghum(Sorghum bicolor L.)

Sucrose nonfermenting-related protein kinase 1(SnRK1)is one of the critical serine/threonine protein kinases.It commonly mediates plant growth and development,cross-talks with metabolism processes and physiological responses to biotic or abiotic stresses.It plays a key role in distributing carbohydrates and sugar signal transporting.In the present study,eight SnRK1 coding genes were identified in sorghum(Sorghum bicolor L.)via sequences alignment,with three forαsubunits(SnRK1α1 to SnRK1α3),three forβ(SnRK1β1 to SnRK1β3),and one for bothγ(SnRK1γ)andβγ(SnRK1βγ).These eight corresponding genes located on five chromosomes(Chr)of Chr1–3,Chr7,and Chr9 and presented collinearities to SnRK1s from maize and rice,exhibiting highly conserved domains within the same subunits from the three kinds of cereals.Expression results via qRT-PCR showed that different coding genes of SnRK1s in sorghum possessed similar expression patterns except for SnRK1α3 with a low expression level in grains and SnRK1β2 with a relatively high expression level in inflorescences.Results of subcellular localization in sorghum leaf protoplast showed that SnRK1α1/α2/α3/γmainly located on organelles,while the rest four of SnRK1β1/β2/β3/βγlocated on both membranes and some organelles.Besides,three combinations were discovered among eight SnRK1 subunits in sorghum through yeast two hybrid,includingα1-β2-βγ,α2-β3-γ,andα3-β3-γ.These results provide informative references for the following functional dissection of SnRK1 subunits in sorghum.

Regulations on Planting Techniques of Harmless Feeding Sorghum bicolor(L.) Moench in Hebei

According to many years of experimental summary, regulations on planting technique of harmless feeding Sorghum bicolor （L.） Moenchwere studied from the application scope, basic demands of planting, preparation be fore seeding, demands of seeding, field management, clipping and harvesting, transportation, storage, ledger management and other technical requirements, and specific measures and technical indicators of the technical regulations were analyzed, so as to provide normalized, standardized, industrial and marketization technical support for the planting of harmless feeding S. bicolor （L.） Moench.

Effect of Planting Date on Yield and Yield Components of Grain Sorghum Hybrids

In Kansas, productivity of grain sorghum [Sorghum bicolor (L.) Moench] is affected by weather conditions at planting and during pollination. Planting date management and selection of hybrid maturity group can help to avoid severe environmental stresses during these sensitive stages. The hypothesis of the study was that late May planting improves grain sorghum yield and yield components compared with late June planting. The objectives of this research were to investigate the influence of planting dates yield and yield components of different grain sorghum hybrids, and to determine the optimal planting date and hybrid combination for maximum biomass and grains production. Three sorghum hybrids (early, medium, and late maturing) were planted in late May and late June without irrigation in Kansas at Manhattan/Ashland Bottom Research Station, and Hutchinson in 2010;and at Manhattan/North Farm and Hutchinson in 2011. Data on dry matter production, yield and yield components were collected. Grain yield and yield components were influenced by planting date depending on environmental conditions. At Manhattan (2010), greater grain yield, number of heads per plant, were obtained with late-June planting compared with late May planting, while at Hutchinson (2010) greater yield was obtained with late May planting for all hybrids. The yield component most affected at Hutchinson was the number of kernels∙panicle−1 and plant density. Late-May planting was favorable for late maturing hybrid (P84G62) in all locations. However, the yield of early maturing hybrid (DKS 28-05) and medium maturing hybrid (DKS 37-07) was less affected by delayed planting. The effects of planting dates on yield and yield components of grain sorghum hybrids were found to be variable among hybrid maturity groups and locations.

Genetic Diversity in the Environmental Conditioning of Two Sorghum (<i>Sorghum bicolor</i>L.) Hybrids

Sorghum metabolism continually adapts to environmental temperature as thermal patterns modulate diurnally and seasonally. The degree of adaptation to any given temperature may be difficult to determine from phenotypic responses of the plants. The present study was designed to see if the efficiency of quantum yield of photosystem II could be used as a measure of how well leaf tissue metabolism was able to withstand a prolonged respiratory demand caused by elevated temperatures. The efficiency of quantum yield values of Pioneer 84G62 and Northrup King KS585 commercial sorghum hybrids showed that when the hybrids were grown in a 28&deg;C/20&deg;C day/night cycle in the greenhouse or the field, Pioneer hybrid 84G62 withstood subsequent elevated thermal challenges better than Northrup King KS585. The same hybrids grown in a 39&deg;C/32&deg;C day/night cycle showed similar efficiency of quantum yield values when thermally challenged. Water-deficit stress increased the heat resistance of the tissue raising the efficiency of quantum yield of both lines to the same level. Upon recovery from the water deficit stress the differential efficiency of quantum yield values between the two lines re-appeared. The data provided in this study suggest a metabolic advantage of Pioneer 84G62 to environmental thermal challenges compared with the Northrup King KS585.

Genome-wide identification,expression and functional analysis of sugar transporters in sorghum(Sorghum bicolor L.)

Sugar transporters are essential for osmotic process regulation,various signaling pathways and plant growth and development.Currently,few studies are available on the function of sugar transporters in sorghum(Sorghum bicolor L.).In this study,we performed a genome-wide survey of sugar transporters in sorghum.In total,98 sorghum sugar transporters(SSTs)were identified via BLASTP.These SSTs were classified into three families based on the phylogenetic and conserved domain analysis,including six sucrose transporters(SUTs),23 sugars will eventually be exported transporters(SWEETs),and 69 monosaccharide transporters(MSTs).The sorghum MSTs were further divided into seven subfamilies,including 24 STPs,23 PLTs,two VGTs,four INTs,three p Glc T/SBG1 s,five TMTs,and eight ERDs.Chromosomal localization of the SST genes showed that they were randomly distributed on 10 chromosomes,and substantial clustering was evident on the specific chromosomes.Twenty-seven SST genes from the families of SWEET,ERD,STP,and PLT were found to cluster in eight tandem repeat event regions.In total,22 SSTs comprising 11 paralogous pairs and accounting for 22.4%of all the genes were located on the duplicated blocks.The different subfamilies of SST proteins possessed the same conserved domain,but there were some differences in features of the motif and transmembrane helices(TMH).The publicly-accessible RNA-sequencing data and real-time PCR revealed that the SST genes exhibited distinctive tissue specific patterns.Functional studies showed that seven SSTs were mainly located on the cell membrane and membrane organelles,and 14 of the SSTs could transport different types of monosaccharides in yeast.These findings will help us to further elucidate their roles in the sorghum sugar transport and sugar signaling pathways.

Agro Morphological Characterization and Evaluation of Three Okra [Abelmoschus esculentus (L.) Moench] Varieties from Zinder (Niger) for Yield and Other Variability Components

Okra, (Abelmoschus esculentus (L.) Moench), is grown as a sole crop and as a field crop in Niger. In the present study, three okra varieties from Zinder region in Niger Republic have been assessed for their agronomic performance traits. The experiment was conducted in a randomized complete block design with three replications during the dry season 2018-2019. The following characters were evaluated: emergence;germination;boutonization flowering;fructificaion;height at flowering;height at maturity;length of the petiole;diameter of leaves;diameter of plants;number of fruits;number of fruit per branch;total number of fruits;number of branch, number of leaves;length of fruits;diameter of fruits;number of arrets;weight of fruits;weight of seed, number of seeds. The collected data were subjected to analysis of variance (ANOVA) using XlStat version 7.1 and the means separated by using Turkey’s Method. Analysis of Principal components (PCA) using R software was also performed on the variables. There were significant differences for all characters except emergence, germination, diameter of plants, number of fruits, total number of fruits and diameter of fruits. The multivariate analysis by the ACP showed a grouping of the varieties in three groups. The three okra varieties have revealed good performances and could be useful for a breeding program. The study of the water needs of the varieties will be very interesting to make a better selection of the collection.

Compounds from the flowers and fruits of Abelmoschus esculentus (L.) Moench

The Abelmoschus esculentus(L.)Moench was previously reported to have various phytochemicals.Chemical fractionation yielded from the ethanolic extract of the A.esculentus ten compounds,including four alkaloids(4-6,8)and six phenolic acids(1-3,7,9-10).The structures of the compounds were elucidated through extensive spectra analyses and comparison of the experimental data with reported data.It is worth mentioning that compounds 1,2 and 5-10 were isolated from Abelmoschus esculentus(L.)for the first time.

PCR Amplification，Cloning and Sequencing of RbcL Coding Region in Mesophyll Cell and Bundle Sheath Cell of Sorghum（Sorghum bicolor L．）

The Primacy question addressed in our study is: Is the difterntial expression of rbcL gene in mesophyll cells and in bundle sheath cells related to the sequence of the gene per se?An enzymatic approach was fist established to separate the two groups of cells. Microscopic examination revealed satisfactory separation effect: minimal mutual contamination was found so that no mistake might be introduced into biochemical or molecular biological expeitments using such preparations. CpDNA were isolated from mesophyll cells and from bundle sheath cells and coding region of rbcL gene was obtained from each by PCR ampilfication.Cloning and sequencing were then done on them.Compartive analysis , however, revealed identical sequence, with a length of 1,368 bp, encoding 456 amino acids. Since sequences of the non-coding regions of rbcL gene in masephyll sad bundle sheath have not been obtained, it can not yet be concluded that the differential expression is not related to the sequence itself. Nevertheless,It sesems justifiable to infer that whatever difference there may be between the sequences of rbcL gene in two groups of cells can only be found in the non-coding regions(including promoter and the 3' down stream region).

基于AFLP和SSR标记的高粱分子遗传连锁图构建

以茎秆糖份含量高的高粱自交系1095和低糖高粱自交系N3杂交获得的F2分离群体(205个个体)为材料,采用AFLP(amplified fragment length polymorphism)和SSR(simple sequence repeat)两种分子标记,构建了包含273个(232AFLP,41SSR)标记,覆盖基因组长度为978.1cM的高粱分子标记连锁遗传图。以SSR标记为锚标记,19个连锁群中,18个连锁群各自被归并于高粱的10个连锁群(A-J)中。该连锁图平均图距和最大图距分别为3.6cM和19.4cM,未出现大的空隙(gap>25cM),归并后的10个连锁群(A-J)分别对应于高粱染色体SBI-01、SBI-02、SBI-03、SBI-04、SBI-07、SBI-09、SBI-10、SBI-08、SBI-06、SBI-05。

高粱两步法厌氧发酵产己酸研究

研究以富含淀粉的高粱为原料,通过两步法厌氧发酵提高己酸生成效率,即第一步分别接种己酸复合菌液、接种嗜酸乳杆菌TYCA06、添加酿酒酵母制得丁酸发酵液、乳酸发酵液、乙醇发酵液,第二步将丁酸发酵液、乳酸发酵液、乙醇发酵液等3种发酵液混合,并接种己酸复合菌液,厌氧发酵制得己酸。研究发现:通过优化丁酸发酵液、乳酸发酵液、乙醇发酵液的发酵工艺,丁酸发酵液中的丁酸、乙酸产量达到20.16 g/L和8.47 g/L,淀粉转化率达到76.02%;乳酸发酵液中的乳酸产量和乳酸产率分别达到11.41 g/L和42.48%;乙醇发酵液中的乙醇产率可达95.06%。继续优化己酸发酵工艺,发现当乙醇发酵液和乳酸发酵液同时作为电子供体时,己酸产量和产率均显著提升,分别达到4.15 g/L和75.2 mg/g,且当乙醇发酵液和乳酸发酵液中乙醇与乳酸添加的质量浓度比为2∶1时,己酸产量和产率均达到最高,分别为6.65 g/L和99.78 mg/g。对己酸发酵过程中微生物与己酸的相关性分析发现,发酵过程中和己酸含量呈正相关的微生物有产己酸菌属(Caproiciproducens)、Clostridium_sensu_stricto_12、Pseudoclavibacter。其中Caproiciproducens随着发酵进行不断富集,到发酵后期相对丰度达到37.81%,是己酸形成的主要贡献者。希望研究可为无外源电子供体添加条件下,实现高粱两步法厌氧发酵生产己酸提供理论基础,为拓展高粱的资源化利用提供思路。

高粱不同器官生长对NaCl胁迫的响应及其耐盐阈值

用砂基培养研究高粱不同器官生长对NaCl胁迫的响应及其耐盐阈值。NaCl胁迫下，独角虎和糖高粱均表现为生长叶叶鞘鲜重下降最大，其次是生长叶叶片、成熟叶叶鞘和叶片变化最小。长期胁迫单株叶片数及叶面积也明显下降。相同胁迫情况下，糖高梁的生长抑制明显大于独角虎。独角虎和糖高粱耐盐阈值分别为135和82mmol／LNaCI。以上结果表明独角虎耐盐能力明显大于糖高粱。讨论了不同器官生长抑制的机制。

HPLC法测定荞麦不同种不同部位槲皮素和山柰酚的含量

目的:采用HPLC法测定荞麦不同种不同部位槲皮素和山柰酚的含量。方法:色谱柱:DIKMA diamonsil(250 mm×4.6 mm,5μm);流动相:乙腈(A)-0.1%磷酸溶液(B),梯度洗脱;检测波长:260 nm;流速:1.0 mL/min;柱温:25℃。结果:苦荞不同部位槲皮素含量为:种子(6.12 mg/g)>叶(1.47 mg/g)>茎(0.34 mg/g),根中未检测到;山柰酚只在种子(0.42 mg/g)和西荞1号叶(0.09 mg/g)中检测到;甜荞根(0.12 mg/g)、茎(0.17 mg/g)、叶(0.32 mg/g)和种子(0.12 mg/g)中均检测到较低含量的槲皮素,未检测到山柰酚;苦荞根、茎和叶中的槲皮素和山柰酚总含量和平均含量都高于甜荞;同一产地不同栽培品种苦荞中槲皮素和山柰酚含量差异不大,甜荞未检测到。结论:该方法方便快速,结果准确,可为荞麦及其产品的质量评价提供依据。

六个生长时期高粱对NaCl胁迫的响应

为了解高粱不同生长时期对NaCl胁迫的响应机制,以高粱杂交品种济粱1号为研究材料,采用自来水(CK)和0.6%NaCl溶液(T)对萌发期、苗期、拔节前期、拔节后期、孕穗期和开花期的济粱1号进行28 d处理。结果表明,与CK相比,萌发期开始NaCl胁迫,其株高、茎粗、地上部鲜重和根干重均差异显著,相对盐害率(RSR)最大,受NaCl胁迫危害最严重。拔节前期NaCl胁迫对穗鲜重影响最显著,其次是拔节后期和孕穗期。拔节前期、拔节后期和孕穗期开始NaCl胁迫对抽穗期影响均不显著。与CK相比,萌发期、拔节后期、孕穗期和开花期开始NaCl胁迫其叶片SPAD值显著降低;与CK相比,6个生长时期进行NaCl胁迫均显著提高了叶片和根中Na^+含量;除萌发期外,NaCl胁迫后,其他5个生长时期叶中K^+含量显著高于CK。在6个生长时期,NaCl胁迫根中K^+含量以及叶片和根中K^+/Na^+显著低于CK。因此,萌发期开始NaCl胁迫对高粱幼苗形态建成影响最大,拔节前期NaCl胁迫对穗鲜重的积累影响最显著,在生产上应采取一定的抗盐胁迫措施。本研究揭示了济粱1号在6个生长时期的耐盐特点和耐盐生理机制,为盐碱地制定科学合理的抗盐栽培管理措施提供了一定的理论指导。

高粱苯丙氨酸解氨酶(SbPAL)编码蛋白的生物信息学分析

高粱是世界上一种重要的粮食作物,具有耐寒耐高温等优良性质,挖掘高粱抗病基因(如PAL),在基因水平上进行遗传改良,提高高粱对贫瘠土地的耐受性仍是研究热点之一。以高粱的苯丙氨酸解氨酶基因(SbPAL)为研究对象,运用生物信息学方法对其编码蛋白的结构、理化性质及功能结构域进行分析,以期揭示苯丙解氨酶的基本信息。结果表明,高粱SbPAL基因的编码序列(Coding sequences,CDS)全长为2 145 bp,编码714个氨基酸;高粱SbPAL蛋白主要位于细胞基质中,二级结构以无规则卷曲和α-螺旋为主,三级结构预测其为同源四聚体结构,由4个相同亚基对称性组成,各亚基之间由配体DTT共价连接。多序列比对结果表明,高粱SbPAL蛋白与拟南芥、水稻、葡萄、烟草等蛋白的同源性较高,为83.31%,SbPAL基因与玉米、水稻和大麦有着较近的亲缘关系,PAL在这些作物中主要参与木质素和植保素的合成。此分析结果将为后续进一步研究SbPAL对木质素、植保素等合成的分子机制与抗病性关系奠定一定的理论基础。

不同施肥量和种植密度对紫锥菊质量的影响

[目的]探究紫锥菊(Echinacea purpurea(L.)Moench)在陕西省凤县的应用潜力及栽培技术。[方法]于2022-2023年开展大田试验,采用二裂式裂区试验设计,以施肥量为主区,共设5个处理F0~F4(施肥量依次为酵母源烟茎生物有机肥:0、1200、2100、3000、3900 kg·hm^(-2);酵母源有机无机复混肥:0、360、630、900、1170 kg·hm^(-2));移栽密度为裂区,设置2个水平,D1(63000窝·hm^(-2))和D2(31500窝·hm^(-2)),平均每窝种植3株,分别在2022年10月、2023年7月和2023年10月采样,测定不同处理紫锥菊株高、茎粗、开花枝条数、叶绿素含量、地上部分干重、根干重等生物学性状,以及地上部分和地下部分菊苣酸、单咖啡酰酒石酸、黄酮、多糖含量和紫锥菊药材产量等指标。[结果]在同一施肥条件下,随着种植密度的增加,紫锥菊的各生物学性状指标降低,除多糖含量以外其它有效成分含量及药材产量随种植密度的增加而增加;在同一栽培密度下,随着施肥量的增加,各生物学性状指标、有效成分含量及药材产量呈现先升高后降低的趋势。施肥量、种植密度以及施肥量和种植密度的互作效应对紫锥菊菊苣酸、单咖啡酰酒石酸、黄酮、多糖含量和紫锥菊药材产量有显著影响(P<0.05)。紫锥菊地上部分菊苣酸、单咖啡酰酒石酸、黄酮含量高于地下部分,而地下部分多糖含量高于地上部分,并且以2023年7月采收的紫锥菊质量及产量最佳。其中F1D1、F2D1处理组有较高的产量及有效成分含量。[结论]推荐紫锥菊种植时施1200~2100kg·hm^(-2)酵母源烟茎生物有机肥和360~630kg·hm^(-2)酵母源有机无机复混肥,种植密度为每公顷63000窝(种植株距为30 cm,行距为60 cm),以获得较高品质和产量的紫锥菊药材。

高粱SBP基因家族鉴定及干旱胁迫下的表达模式分析

在高等植物中,SQUAMOSA Promoter Binding Protein-Box(SBP)普遍参与植物的生长、开花调控及细胞程序性死亡等过程。本研究对高粱(Sorghum bicolor L.)SBP转录因子家族进行鉴定并进行生物信息学分析,同时利用qRT-PCR对高粱SBP基因在PEG-6000模拟干旱胁迫下的表达进行分析,以验证其功能。结果表明,从高粱中共鉴定出19个SBP成员,除第8条染色体外,其他9条染色体上均分布有SBP基因;绝大部分SBP蛋白在亚细胞水平定位于细胞核,且均为亲水性蛋白质。系统发育分析结果表明,与水稻类似,这19个高粱SBP基因也可分为3个亚类,分别含有7、5、7个SBP基因;相比于拟南芥,高粱SBP与水稻、玉米的SBP关系更近。启动子顺式作用元件预测结果显示,高粱SBP可能参与了脱落酸、茉莉酸甲酯信号通路,部分成员可能与植物的低温响应、昼夜节律调控有关。qRT-PCR分析结果显示,高粱SBP基因的表达具有组织特异性,有17个基因受干旱胁迫诱导上调表达,且随胁迫时间的延长存在差异化表达模式。本研究结果可为后续研究高粱SBP基因的功能提供理论依据。

Transcriptomic profiling of sorghum leaves and roots responsive to drought stress at the seedling stage

Drought stress affects the growth and productivity of crop plants including sorghum.To study the molecular basis of drought tolerance in sorghum,we conducted the transcriptomic profiling of sorghum leaves and roots under drought stress using RNA-Seq method.A total of 510,559,and 3 687 differentially expressed genes(DEGs)in leaves,3 368,5 093,and 4 635 DEGs in roots responding to mild drought,severe drought,and re-watering treatments were identified,respectively.Among them,190 common DEGs in leaves and 1 644 common DEGs in roots were responsive to mild drought,severe drought,and re-watering environment.Gene Ontology(GO)enrichment analysis revealed that the GO categories related to drought tolerance include terms related to response to stimulus especially response to water deprivation,abscisic acid stimulus,and reactive oxygen species.The major transcription factor genes responsive to drought stress include heat stress transcription factor(HSF),ethylene-responsive transcription factor(ERF),Petunia NAM,Arabidopsis ATAF1/2 and CUC2(NAC),WRKY transcription factor(WRKY),homeodomain leucine zipper transcription factor(HD-ZIP),basic helix-loop-helix transcription factor(bHLH),and V-myb myeloblastosis viral oncogene homolog transcription facotr(MYB).Functional protein genes for heat shock protein(HSPs),late-embryogenesis-abundant protein(LEAs),chaperones,aquaporins,and expansins might play important roles in sorghum drought tolerance.Moreover,the genomic regions enriched with HSP,expansin,and aquaporin genes responsive to drought stress could be used as powerful targets for improvement of drought tolerance in sorghum and other cereals.Overall,our results provide a genome-wide analysis of DEGs in sorghum leaves and roots under mild drought,severe drought,and re-watering environments.This study contributes to a better understanding of the molecular basis of drought tolerance of sorghum and can be useful for crop improvement.

Pseudogamous Apomixis in Maize and Sorghum in Diploid-Tetraploid Crosses

Apomictic seed development is a complex process including formation of unreduced embryo sac,parthenogenetic embryo development from the egg cell,and endosperm formation either autonomously,or due to fertilization of polar nuclei by the sperm(under pseudogamous form of apomixis).In the latter case,an obstacle to the normal endosperm development is disturbance of maternal(m)-to-paternal(p)genomic ratio 2m:1p that occurs in the cases of pollination of unreduced embryo sac with haploid sperms.Usage of tetraploid pollinators can overcome this problem because in such crosses maternal-to-paternal genomic ratio is 4m:2p that provides formation of kernels with plump endosperm.Using tetraploid lines as pollen parents we observed formation of plump kernels on the ears and panicles of diploid maize and sorghum accessions.These kernels had hybrid endosperm and diploid maternal-type embryo or hybrid embryo with different ploidy level(2n,3n,4n).The frequencies of plump kernels on the ear ranged from 0.2-0.3%to 5.7-6.2%counting from the number of ovaries.Maternal-type plants were found in two maize lines,their frequency varying from 10.7 to 37.5%of the progeny plants.In CMS-lines of sorghum pollinated with tetraploid sorghum accessions,the frequency of plump kernels ranged from 0.6 to 14.0%counting from the number of ovaries;the frequency of maternal-type plants varied from 33.0 up to 96.1%.The hybrid nature of endosperm of the kernels that gave rise to maternal-type plants has been proved by marker gene expression and by SDS-electrophoresis of endosperm proteins.These data testify to variable modes of seed formation under diploid×tetraploid crosses in maize and sorghum both by amphi-and by apomixis.Therefore,usage of tetraploid pollinators might be a promising approach for isolation of apomixis in maize and sorghum accessions.