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1.
基于PLC的苔麸播种机设计与试验 总被引:2,自引:0,他引:2
设计了一种基于PLC的苔麸施肥播种机。该播种机主要由排种器、开沟器和PLC控制器等关键部件组成,通过转速传感器测量播种速度,建立播种速度和伺服电动机转速之间的对应关系,通过控制伺服电动机转速实现不同播种速度下单位面积播种量一致。在播种量4、5、6kg/hm2,播种速度3、4、5km/h条件下,进行了排种器性能测试,播种量5kg/hm2条件下,得到各行排种量一致性变异系数5.02%,总排种量稳定性变系数0.89%,种子破损率0.1%,试验零水平时排种均匀性变异系数18.9%,满足标准要求;田间试验结果表明播种均匀性变异系数20.4%,满足苔麸农艺要求。 相似文献
2.
Recombinant inbred lines (RILs) of the tef cross Kaye Murri × Fesho were evaluated for nine quantitative traits at three locations
in the central highlands of Ethiopia during the 1998/99 main season in order to estimate the genetic coefficient of variation
(GCV), heritability and genetic advance expected from selection. Highly significant differences were obtained among the RILs
for all traits studied. Grain yield, panicle weight and yield per panicle showed a relatively high GCV (12–16%). A comparatively
high heritability was obtained from days to heading (31%) followed by panicle length (25%) and grain yield (23%). Moderate
amounts of heritability values were obtained for panicle weight and yield per panicle. High genetic advance as percent of
the mean were obtained from grain yield (16%), yield per panicle (12%) and panicle weight (10%) at5% selection intensity,
which indicated the possibility of improving these traits. Several RILs were identified that have exceeded the better yielding
parent at all locations. Grain yield showed a strong positive association (r = 0.26–0.70) with shoot biomass, lodging index,
panicle length, plant height, panicle weight and yield per panicle. Overall, the present results showed a) the availability
of genetic variance for some useful traits in the RILs for exploitation through selection, b) the existence of significant
genotype × location interaction that indicated the need to test inbred populations in more environments, and c)the availability
of superior inbred lines for further breeding work.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
3.
4.
Kebebew Assefa Seyfu Ketema Hailu Tefera Henry T. Nguyen Abraham Blum Mulu Ayele Guihua Bai Belay Simane Tiruneh Kefyalew 《Euphytica》1999,106(1):87-97
Three hundred twenty germplasm lines of the major Ethiopian cereal, tef, [ Eragrostis tef (Zucc.) Trotter], were evaluated
for 20 morphological, phenological and agronomic characters in two-replicated randomized complete blocks at Debre Zeit and
Melkassa Agricultural Research Centers in Ethiopia during the 1995 main season. The objectives were to assess the diversity
of the lines, and to estimate the broad sense heritability (H) and genetic advance (GA) of the various characters. The mean
squares of genotypes were highly significant (p ≤ 0.001) for all the traits. The phenotypic and genotypic coefficients of
variation ranged in that order from about 6–40% and 3–23% for days to maturity and grain yield/plant, and days to maturity
and number of spikelets/main shoot panicle, respectively. The cluster analysis grouped the genotypes into 14 major complexes
consisting of one to 183 lines. Of the 19 principal components involved in explaining the entire variation among the genotypes
the first five which had eigenvalues of more than one explained about 73.8%. The first principal component which accounted
for about 34% of the total variance was due chiefly to plant height, culm and panicle length, diameters of the two basal culm
internodes, main shoot panicle mass and grain yield, number of main shoot panicle branches and spikelets, and days to panicle
emergence and maturity. Estimates of H varied from about 22% for length of the lowest main shoot stem internode to 74% for
number of main shoot panicle branches. Values of GA (expected from selection of the superior 5% of the lines and expressed
relative to the means) ranged from about 3% for days to maturity to 36% for number of spikelets/main shoot panicle. Overall,
the study indicated the existence of trait diversity in tef germplasm and this can be exploited in the genetic improvement
of the crop through hybridization and selection.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
5.
Gene action controlling yield and yield‐related traits among tef (Eragrostis tef [Zucc.] Trotter) populations under drought‐stressed and nonstressed conditions 下载免费PDF全文
This study was aimed to determine gene action for grain yield and yield‐related traits of newly developed tef populations under drought‐stressed and nonstressed conditions to improve drought tolerance. Ten crosses, along with the parents, were evaluated in the F2 generation under drought‐stressed conditions at Hastebo and Adigdad sites in 2015 and Dura site in 2016 and under nonstressed conditions at Dura site in 2016. Additive gene action predominantly controlled the inheritance of the grain yield and majority of the yield‐related traits under drought‐stressed and nonstressed conditions. Under both test conditions, the genotypes DZ‐Cr‐387 and 9415 were the best general combiners for increased grain yield and morphological traits. Conversely, genotype 222076 was the best general combiner for reduced maturity period only. The selected parents are novel genetic materials for tef breeding programmes to improve grain yield and morphological traits with reduced days to maturity for drought tolerance breeding. The family of the cross DZ‐Cr‐387 × 222076 was selected for high grain yield and early maturity in both the drought‐stressed and nonstressed environments. 相似文献
6.
Wheat flour replacement from 0 to 40% by single tef flours from three Ethiopian varieties DZ-01-99 (brown grain tef), DZ-Cr-37 (white grain tef) and DZ-Cr-387 (Quncho, white grain tef) yielded a technologically viable ciabatta type composite bread with acceptable sensory properties and enhanced nutritional value, as compared to 100% refined wheat flour. Incorporation of tef flour from 30% to 40% imparted discreet negative effects in terms of decreased loaf volume and crumb resilience, and increase of crumb hardness in brown tef blended breads. Increment of crumb hardness on aging was in general much lower in tef blended breads compared to wheat bread counterparts, revealing slower firming kinetics, especially for brown tef blended breads. Blended breads with 40% white tef exhibited similar extent and variable rate of retrogradation kinetics along storage, while brown tef-blended breads retrograded slower but in higher extent than control wheat flour breads. Breads that contains 40% tef grain flour were found to contain five folds (DZ-01-99, DZ-Cr-387) to 10 folds (DZ-Cr-37) Fe, three folds Mn, twice Cu, Zn and Mg, and 1.5 times Ca, K, and P contents as compared to the contents found in 100% refined wheat grain flour breads. In addition, suitable dietary trends for lower rapidly digestible starch and starch digestion rate index were met from tef grain flour fortified breads. 相似文献
7.
Osmotic adjustment (OA) and deep roots were shown to be important drought resistance mechanism in many crop plants. In this
study, geno types systematically selected from an Ethiopian endemic tef [Eragrostis tef (Zucc) Trotter] germplasm pool were evaluated for osmotic adjustment and root depth in greenhouse in several experiments.
The association of these traits with other plant characters was also studied. Osmotic adjustment was investigated in two experiments.
Experiment 1 was conducted using nine genotypes for two seasons (spring and fall 1996), and experiment 2 was undertaken in
the spring of 1997 with 45 genotypes. In experiment 1, there were significant genotype effects on OA. Though there was also
significant genotype by season interaction for OA, some of the extreme lines gave consistently high (Ada and DZ-01-99) and
low (DZ-01-354 and Trotteriana) OA values across seasons. There was a significant variation among genotypes for OA in experiment
2. Osmotic adjustment was not associated with the altitude of the region of origin of the particular tef genotype. In both
experiments, OA was significantly correlated across tef genotypes with delayed wilting and the maintenance of higher relative
water content (RWC) under conditions of soil moisture stress. Three experiments were conducted to evaluate the phenotypic
diversity for root depth. In all experiments tef genotypes differed significantly for root depth as measured at flowering
time. The late maturing genotypes tended to have greater root depth as compared to early maturing genotypes. Root depth was
not associated with the altitude of the region of origin of the tested genotypes. There was no association between root depth
and OA across genotypes.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
8.
生防长枝木霉菌培养特性及形态学与系统发育学鉴定 总被引:1,自引:0,他引:1
采用宏观观察法和显微镜镜检的方法,在PDA和MEA培养基上对1株自我采集的具有生防价值的木霉菌株T05进行了培养特性和形态学研究。结果表明:该菌株在PDA平板培养基上生长较快,产分生孢子较早且多,也能产生厚垣孢子;在MEA上能产生分生孢子,但不产生厚垣孢子。该菌株产孢簇为松散羊毛状到紧实的疱状结构;分生孢子梗具有较简单的分枝系统,通常呈直角的1~2次分枝,单生或有时成对。瓶梗不规则地在侧面分布,时常单生,安瓿形或柱形,基部常缩缢但不明显;分生孢子单细胞、长方形到椭圆形、绿色、光滑,大小为(2.0~3.0)μm×(2.0~6.0)μm。根据这些形态特征将菌株T05鉴定为长枝木霉(Trichoderma longibrachiatum)。在此基础上,对T05的rDNA转录间区序列ITS和翻译延伸因子基因tef1-α的第5内含子序列进行了扩增、测序。系统发育学的研究表明,该菌株的ITS序列和tef1-α的第5内含子序列与长枝木霉的多个菌株都具有最大的相似性,因此属于长枝木霉。 相似文献
9.
Three thousand tef [Eragrostis tef (Zucc.) Trotter] single panicle derived lines representing 60 populations from western and southern parts of Ethiopia were
characterized for panicle form, pigmentation of lemma and anther, caryopsis color, number of main shoot culm internodes, and
counts of florets/spikelet at the basal, middle and apical parts of the panicle at Debre Zeit Agricultural Research Center
during the 1999 main season. The objectives were to assess the diversity patterns of the germplasm with respect to regions
and altitude zones. Among the eight characters, high Shannon-Weaver diversity indices (H’) were noted for anther color (0.71)
and number of apical spikelet florets (0.68), and the lowest occurred for panicle form (0.40). Monomorphism (H’ = 0.00) was
observed for panicle form, lemma color and number of middle spikelet florets each in three different populations. The overall
diversity index for all populations was 0.53. In the analysis of variance of H’ estimates, substantial (p <0.05) regional differences were obtained for lemma color, number of culm internodes, and counts of middle and basal spikelet
florets. Clinal variation was significant for panicle form, lemma and seed color, and for the overall mean of traits. Over
all traits, mean H’ values declined from 0.60 to 0.46 with an increase in the altitude zone of origin from below 1800 to over
2400 meters above sea level. Overall, the study showed substantial diversity in the test tef germplasm.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
10.
The normal and selfed families of the triple test cross were employed to detect gene action in t'ef for grain yield and other
useful agronomic characters in the breeding programme. Cultivars Kay Murri and Fesho were used as L1 and L2 testers, respectively. Eight randomly selected cultivars and two released varieties (DZ-01-354 and DZ-01-196) were crossed
with the testers L1, L2 and L3 (the F1 of L1 × L2). In the case of the selfed families, 14 cultivars and two released varieties were used for crossing with the testers. The
normal families were grown on an Inceptisol developed from volcanic ash whilst the selfed families were grown on a pellic
Vertisol at the Debre Zeit Agricultural Research Centre, Ethiopia. The rainfall during the experimental season was 463 mm.
Epistasis was detected for grain yield, yield per panicle, panicle weight, plant weight, harvest index, tiller number, panicle
length, culm diameter, days to heading and days to maturity in the normal families of the triple test cross (TTC) of t'ef.
Similarly the characters grain yield, yield per panicle, panicle weight, plant height, panicle length, days to heading and
days to maturity showed epistasis in the selfed families of the TTC. Epistatic interaction was not important for shoot biomass
and for harvest index (for the transformed data) in this family. Therefore, both the normal and selfed families of the TTC
were in agreement with regard to detecting epistasis for grain yield, yield per panicle, panicle weight, panicle length, days
to heading and days to maturity. Significant additive (D) and dominance (H) components were estimated for the characters in
both families, although the magnitudes might have been inflated due to epistasis. The dominance component for panicle length
was unimportant in both families of the TTC and as a result the additive components were not biased. In general, the additive,
dominance and epistatic components were important in t'ef. Since the crop is self-fertilized only the additive and additive
× additive terms are important to develop pure breeding varieties. Therefore, selection for superior segregants should start
in advanced generations as homozygosity increases.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献