二棱啤酒大麦杂种一代及其亲本主要性状的灰色系统分析

研究采用灰色关联分析方法,对20组二棱型啤酒大麦杂种一代及其亲本的7个主要性状之间的关联系数、关联度和关联序进行了分析。结果表明：在关联度和关联序中,大麦的穗粒数、穗粒重,千粒重分别与穗长这一性状的关联度最大,关联序中穗长全排在首位;而穗粒数,穗粒重,千粒重分别与有效穗数这一性状的关联度最小,关联序中有效穗数全排在末位,为了提高单株产量应注意协调好有效穗数与穗长这一对主要矛盾明确各性状对籽粒产量所起的直接和间接作用及其相对重要性,确定主攻方向,配制各种优势组合。为大麦亲本选配提供科学依据。从而达到二棱型啤酒大麦预期的育种目标。     

Somatic hybridization of an atrazine resistant biotype of Solanum nigrum with Solanum tuberosum

Summary Twelve varieties of tomato of economic importance and their hybrids (including reciprocals) were studied in four environments: inside and outside of greenhouses and with and without plastic mulching. Seven characters were recorded per plant per environment: (1) total yield, (2) fruit weight, (3) locules/fruit, (4) fruits/cluster, (5) earliness in maturity, (6) earliness in harvesting and (7) leaves between clusters. There was an almost general tendency for hybrids to show higher values than the parentals for characters (1), (4) and (7); the opposite was true for (2) and (3), even when the differences were not statistically significant at the 5% level. Environments were always highly significant; the effect of the greenhouse explained most of the variation. Genotype-environment interaction by regression analysis showed that the performance of the hybrids was generally higher than that of the parents for characters (1), (4) and (7). Total yield was higher, in general, in the most protected environments. Locules per fruit was very constant but when interaction did exist, the number of locules was higher in the less protected environments. Hybrids interacted with environments more strongly than parent lines. Earliness was the most environmental dependent characteristic the choice of early harvesting being irrelevant. Some of the hybrids obtained seem promising from a commercial point of view.     

The Effect of Speckled Leaf Blotch on Apical Development and Yield in Winter Wheat in New Zealand

Speckled leaf blotch (Mycosphaerella graminicola) reduced yieldin a winter wheat trial by 18 per cent. Detailed analyses ofthe effects of disease on yield components showed that diseasereduced both grain number per ear and grain weight. The reductionin grain number per ear was due to a decrease in grain numberper spikelet, and this occurred for both main stem and tillers,and occurred equally at each spikelet position on the ear. The effect of disease on grain number was traced back to anearlier reduction in floret primordium number per ear, especiallyfloret number per spikelet. It was suggested that floret primordiumproduction was affected by the reduced assimilate supply tothe developing apex. The effects of disease on yield could therefore be attributedto effects on plant development both before and after anthesis.The disease effects on yield were not necessarily associatedwith the time of maximum disease severity. Plots with the early phase of disease epidemic only showed asignificant reduction in yield, but there was some evidenceof compensation for early reductions to yield potential in thelater-determined yield components. We suggest, therefore, thatan effective disease-control programme must take into accountthe possible early effects of disease on yield potential. Mycosphaerella graminicola, speckled leaf blotch, winter wheat, yield loss, apical development     

The Influence of the Rht1 and Rht2 Alleles on the Growth of Wheat Stems and Ears

A field experiment was carried out with a set of near-isogenicspring wheat lines (cv. Triple Dirk) to determine the influenceof the Rht₁ and Rht₂ alleles on the partitioning of dry matterbetween the developing stem and the ear. Each line was sampledtwice weekly and dissected into its component above-ground parts.The rate of change of the dry mass of the individual plant organswas expressed as a proportion of the rate of change of the totalplant dry mass. This ratio was used to assess the relative sinkstrengths of the stem and ear during crop growth. The Rht₁ andRht₂ alleles reduced plant height, but increased grain yield.The greater yield was achieved through a greater grain numberper ear in the Rhtl line, a greater ear number per plant inthe Rht₂ line, and a greater allocation of assimilate to thedeveloping ear than to the developing stem in both Rht lines,particularly at the time of maximum stem growth (17 d beforeanthesis). From the earliest stages of detectable ear growthuntil anthesis, the ear masses per unit area of the Rht₁ andRht₂ lines exceeded that of Triple Dirk (Rht). It was not possibleto determine whether the Rht₁ and Rht₂ alleles were directlyresponsible for increasing grain number per ear and ear numberper plant, respectively, since the increase in these componentsof yield could equally be explained by a greater partitioningof assimilate to developing ears and tillers caused simply bya reduction in plant height. Triticum aestivum L., wheat Rht genes, stem and ear development, dry matter partitioning, allocation ratio     

Effect of Defoliation During the Early Vegetative Phase and at Silking on Growth of Maize (Zea mays L.)

Two experiments were conducted in the glasshouse and in thefield to evaluate the effect of leaf loss on development, drymatter accumulation and yield of maize. In the glasshouse, defoliationtreatments were imposed on maize after 3 weeks of planting.Removing 2 or 3 leaves every 2 weeks affected plant height,days to tassel, root and shoot yield. The plant diameter androot:shoot ratio were not affected by defoliation. In the field experiment, six defoliation treatments were imposed7 days after 50 per cent silking. Defoliation of all leaveswas the most severe treatment on cob d. wt, dry matter accumulationin grains, weight of 100 test grains and yield. The effect ofremoving all leaves above the ear was not significantly differentfrom that of removing all leaves below the ear. The effect ofremoving half of the leaves above the ear was not differentfrom the control. Zea mays, vegetative growth, dry matter accumulation, yield, defoliation     

阴湿环境对玉米杂交种生长发育特性的影响

比较了在人工遮光增湿环境和自然环境下18个玉米杂交种生长发育特性的差异,研究了阴湿环境对玉米杂交种生长发育特性的影响.结果表明: 遮光增湿环境使空气湿度比自然环境增加15.0%～16.4%,土壤湿度增加27.0%～78.4%,光照强度降低72.9%～77.9%,光量子减少72.8%～79.6%,差异均达显著或极显著水平,但不影响环境温度.阴湿环境导致玉米植株第7叶宽、有效功能叶数、成株叶片数、雄穗分枝数、茎粗、株高、穗位高、穗长、穗粗、穗行数、行粒数、百粒重和单株粒重13个性状表现为负向变异(表型值变小),其中单株粒重降幅达72.3%,株高降幅7.1%,其余性状降幅介于14.8%～53.8%之间;第7叶长、第7叶长宽比、散粉至抽丝间隔天数(ASI)、小斑病指数和纹枯病指数等5个性状表现为正向变异(表型值增大),分别增大39.8%、80.5%、114.3%、73.0%和54.8%.用ASI、雄穗分枝数、成株叶片数、株高、单株粒重、小斑病指数和纹枯病指数7个性状计算出的综合耐阴湿系数作为玉米杂交种耐阴湿鉴定的指标,具有一定的可靠性,且简便易行.运用该指标可将18个杂交种划分为耐阴湿性强、耐阴湿性中等和耐阴湿性弱3类.     

辣椒杂种一代生化特性与农艺性状的灰色关联分析

用灰色关联分析方法研究了辣椒雄性不育杂种一代农艺性状与单株产量间、花蕾、叶片中生化物质含量与农艺性状间关系的密切程度。结果表明,农艺性状与单株产量问关联度的大小顺序依次为株幅、株高、果长、结果数、单果质量、第一花节位、果宽和侧枝数,花蕾中生化物质含量与农艺性状问总体关联度的大小顺序依次为可溶性糖、可溶性蛋白质、过氧化物酶活性、脱落酸、生长素、游离脯氨酸和玉米素,叶片中生化物质含量与农艺性状问总体关联度的大小顺序依次为可溶性糖、过氧化物酶活性、游离脯氨酸、脱落酸、生长素、玉米素和可溶性蛋白质。     

A Physiological Analysis of the Branching Pattern in Sequential Types of Groundnut in Relation to the Fruiting Nodes and the Total Mature Pods Produced

The branching pattern of eight sequential branching types ofgroundnut was studied and the contribution of each node (fruitingpoint) of the n, n+1 and n+2 branches (if present) to the totalnumber of mature pods per plant ascertained. The results indicatedthat n+2 branches were present in several varieties and theircontribution to mature pods was significant in some of them.The first three nodes of the n+1 branches contributed from 50.6per cent (in a variety which had significantly more n+2 branches)to 88 per cent in other varieties. The results also indicatedthat the contribution of the late formed n+1 branches was lowand the total mature pods produced from all nodes decreasedwith each successive (chronologically) n+1 branch in all thevarieties studied. Neither the total number of n+1 branchesnor the number of mature pods per node was related to the podnumber or pod yield, but the total number of fruiting pointsfrom all branches showed a high correlation with pod yield andmature pod number at harvest. The results suggest that for higherpod yield it may be desirable to have only a few n+1 branches(4 or 5) but with more fruiting points on each branch. Arachis hypogaea, branching pattern, sequential types, fruiting points     

盐碱地耐盐小麦覆膜栽培高产机理的研究

通过测定不同ＮａＣｌ浓度下不同小麦品种的发芽率（Ｇｒ）、发芽指数（Ｇｉ）和活力指数（Ｖｉ）及盐渍土壤上的产量筛选出耐盐小麦品种德抗９６１。研究了覆膜穴播对土壤温度、土壤含水量、土壤含盐量、产量及其构成因素、旗叶离子含量和旗叶光合作用特性的影响。结果表明,覆膜明显提高土壤温度和土壤含水量,抑制返盐。覆膜减少Ｎａ＾＋在旗叶中的积累,增加旗叶Ｋ＾＋含量。覆膜显著增加旗叶净光合速率、蒸腾速率,气孔导度和细     

The Influence of Genes for Vernalization Response on Development and Growth in Wheat

Studies were made of the influence of genes for vernalizationresponse on the growth and development of four near-isogeniclines of bread wheat (Triticum aestivum L.). The duration from sowing of flower initiation, terminal spikeletformation and ear emergence all increased with increasing vernalizationresponse. There was a close positive relationship between thedays from sowing to flower initiation and from sowing to earemergence, indicating that the duration of either phase of developmentis a useful measure of relative vernalization when daylengthdoes not limit the rate of development. Total spikelet number per ear and the duration of spikelet initationincreased with increasing vernalization response and there wasa correspondingly higher rate of spikelet initiation in thetwo lines with stronger vernalization response. Most of the differences in growth between the lines were associatedwith diferences in development caused by the vrn genes. Maximumtotal above-ground dry matter and total leaf area per plantincreased with increasing vernalization repsonse but relativegrowth rate and leaf area per plant were not significantly differentbetween the lines. There were no differences in net assimilationrate between the four lines until 40 d from sowing; thereafterit decreased, with the greatest decrease in the line with thestrongest vernalization response. Flower initiation, terminal spikelet formation, spikelet initiation, ear emergence, growth rate     

Estimation of genetic parameters in barley (Hordeum vulgare L.)

Summary Four exotic and four indigenous strains of barley were used for making diallel crosses. The sets of parents and crosses making full, half and quarter diallel were analysed in a randomized block design for plant height, number of effective tillers, ear length, grain yield per plant, 100 grain weight and number of grains per ear.The three alternatives of diallel were similar with respect to the estimates of degree of dominance, general combining ability and specific combining ability, indicating that all these three methods of diallel were equally efficient. However, as the number of entries are minimum in quarter diallel, it would be economical in terms of cost, time and labour to estimate genetic parameters by this method. Average degree of dominance was found in the range of overdominance. The ranking of parents on the basis of their array mean was similar to the ranking based on gca effects. Similarly, the ranking of crosses on the basis of per se performance was similar to the ranking based on sca effects. This suggests that the selection of best general combiner or best cross combinations may be easier and more effective through array mean for per se performance rather than through high gca and sea effects, respectively. From among 56 crosses, IB-226 X X C-164 was the one which showed superiority for maximum number of characters followed by AB-12/59 X PTS-57. High sea effect for plant height, ear length, grain yield, 100 grain weight and number of grains per ear was the result of cross between parents having high X low general combining ability, indicating additive X dominance type of gene interaction. For number of effective tillers, high sca was produced by low x low general combiners, indicating dominance x dominance gene interaction.Part of a Ph. D. thesis submitted by senior author to Haryana Agricultural University, Hissar.     

Efficiency of early generation selections for yield and related characters in safflower (Carthamus tinctorius L.)

The efficiency of early generation selection for yield and related characters in safflower (Carthamus tinctorius L.) was studied in the F₂, F₃ and F₄ generations. Twenty-five F₂ progenies derived from various crosses were studied. In the F₂ generation, number of capitula per plant (CNSP), number of seeds per capitulum (SPSP), test weight (SWSP), and seed yield (SYSP) were the criteria used for single plant selection. The analysis of variance showed significant differences for all of the characters in the F₂, F₃, and F₄ generations. The analysis of variance in each of the selection classes showed highly significant genotypic differences. A large number of selections in the CNSP and SYSP classes showed greater yield than the check variety. In each class the mean for that particular character showed a positive shift. The observed F₃ and F₄ means for seed yield per plant was higher in SYSP, indicating the effectiveness of single plant selection for yield. Correlated response showed that selection for number of capitula per plant was effective for improvement of yield.     

Variation in monoculture and in mixture for grain yield and other characters in spring barley

Fourteen north-west European spring barley cultivars were grown alone or in binary mixtures sampled according to a partial diallel scheme. On the basis of the association between cultivars in mixture and monoculture, three groups of characters were distinguished. Group A characters, plant height, ear weight/tiller, grain yield/tiller, number of grains/tiller and 1000-grain weight, showed strong positive associations between performance in monoculture and mixture. Group B characters, number of tillers/plant and harvest index showed incomplete positive associations, while for group C characters, dry matter/plant, ear weight/plant, grain yield/plant and number of grains/plant, associations were weak or non-existent. Compound characters in group C showed less genetic variation in monoculture and lower general competitive effects in mixture than component characters in groups A or B. These results clearly indicate that while selection for grain yield and other characters on a per plant basis (group C characters) is confounded by intergenotypic competition, characters such as the yield components number of grains/tiller and 1000-grain weight (group A characters) are hardly affected in this range of cultivars. Selection for opposing group A characters may start in the F₂ generation, while any selection for group B and C characters should be delayed until later generations. The merits of indirect selection for yield using visual assessment of yield components are discussed. Separate analyses obtained by the inclusion of spring wheat cv. Timmo in monoculture and in the set of mixtures indicated that the use of spring wheat plants to minimise intergenotypic competition ranges from superfluous (group A characters) to useless (group C characters). A large degree of mixture advantage and the lack of complementary dominance and suppression between competitor and associate was attributed to the relatively low density of plants in the experiment which, though suitable for single plant selection, is not typical of normal seed rates for cropping.     

Yield and yield components in flue-cured tobacco and their genetic analysis

Five cultivars and the half diallel set of 10 F₁ hybrids of flue-cured tobacco (Nicotiana tabacum L.) were grown in two seasons. Highly significant differences were assessed between genotypes as concerns flowering time, plant height, number of leaves, leaf length and width and yield per plot. High to moderate values for heritability in the broad sense were obtained in all cases. Hybrids, in general, flowered earlier, were taller, had fewer but shorter and wider leaves and slightly increased yield when compared with the mean value of all parents. The variance associated with general combining ability (GCA) was highly significant in all characters. The estimates of SCA were significant in most cases. High GCA/SCA ratios which largely exceeded the unity were obtained for most attributes. The negative and positive alleles were unequally distributed in the parents for all the studied traits. A small number of effective genes was obtained for all characters except plant height, where one to two groups of genes were distinguished     

The anther-culture response of triticale line x tester progenies

Seven triticale cultivars (Ampiac, Aubrac, Trinidad, Ticino, Lamberto, Pronto and Prado) and their F1 hybrids obtained after crossing in a line x tester scheme were examined with respect to their androgenetic effectiveness. The embryo induction rate (number of embryos per 100 anthers), green plant regeneration rate (number of green plantlets per 100 embryos), plant yield (number of green and albino plantlets per 100 anthers) and green plant yield (number of green plantlets per 100 anthers) were assessed. The multivariate and univariate effects of general (GCA) and specific (SCA) combining abilities for the studied traits were estimated and tested. Significant differences between the genotypes were found for individual traits as well as for all the traits treated jointly. Hybrids generally showed a better response in anther culture than their parental genotypes. Heterosis effects were observed in some hybrids for embryo induction rate and green plant yield. GCA and SCA variances were significant and a dominance of the GCA over the SCA variation was found. Among the examined cultivars, Ticino and Pronto were characterised by positive and significant GCA for embryo induction and green plant yield, and these cultivars may be recommended for the improvement of anther culture responsiveness in triticale.     

Epistatic,additive and dominance variation in a triple test cross of bread wheat (Triticum aestivum L.)

Summary Triple test cross progenies resulting from the crossing of three testers (Kloka, UP 368 and an f₁ intermediate between them) and 24 varieties of bread wheat have been studied for plant height (cm), peduncle length (cm), ear length (cm), number of spikelets per spike and harvest index (ratio between economic and total yield). Epistasis was not significant for any of the characters studied. The testers were inadequate for plant height and for peduncle length although the testers varied considerably for these traits. Additive variance played a significant role in the inheritance of all the characters except number of spikelets per spike. The dominance variance was important for plant height, ear length and harvest index. The degree of dominance was in the over-dominance range for plant height. Complete dominance was operative for ear length, number of spikelets per spike and harvest index whereas for peduncle length only partial dominance was observed. The possibility of the isolation of the recombinants with high harvest index has been stressed.     

The Effect of New Tiller Growth on Carbohydrates, Nitrogen and Seed Yield per Ear in Lolium perenne L.

To clarify whether new vegetative tillers that develop aroundanthesis in aLolium perenne seed crop can depress seed yields,the possible competition for carbohydrates or nitrogen betweenthe seeds and new tillers that develop after the onset of anthesiswas investigated. In two greenhouse experiments the number oftillers per plant was varied by a combination of cutting, nitrogensupply, light quality and light intensity treatments. Two genotypeswith different tillering rates were used. Seed yield per earwas largely independent of the number of tillers and regrowthof cut tillers after the onset of anthesis. It increased inone genotype, but only under low light and a reduced nutrientavailability, and no new tillers were produced. The amount ofwater-soluble carbohydrates in the reproductive tillers increasedin both clones under these conditions. Under more favourableconditions the increased tillering rate and regrowth of tillersafter cutting did not adversely affect seed yield per ear ineither clone, although carbohydrate reserves in the floweringtillers were sharply reduced. Tiller removal increased the concentrationand amount of nitrogen in the remaining flowering tillers, irrespectiveof the amount of regrowth. It is concluded that competitionfor carbohydrates or nitrogen between the seeds and new vegetativetillers that develop after the onset of anthesis, is not a majorcause of the low and variable seed yields inL. perenne seedcrops. Processes within the ear itself are probably limiting. Lolium perenne L.; perennial ryegrass; seed yield; seed set; tillering; carbohydrates; nitrogen; competition.     

不同绿豆突变体主要农艺性状的多元遗传分析

对12个绿豆突变体的10个主要农艺性状进行了相关分析、主成份分析及聚类分析.分析结果表明：10个主要农艺性状的变异系数为16.01%（单株荚数）～3.64%（荚宽）.相关分析表明单株荚数与单株产量呈极显著的正相关;百粒重与单株产量呈显著的负相关;生育期与单株产量呈极显著的负相关.主成分分析结果表明前4个主成分（产量构成因子、单荚粒数因子、株型因子和荚宽因子）对变异的贡献率达87.45%;聚类分析后把12个绿豆突变体分为5类,各类之间单株产量差异明显.在绿豆突变体的选择中只有把不同性状综合考虑进去,才能够真正选择出性状优良的突变体.     

Decreased whorl and ear damage in nine mon810 Bacillus thuringiensis (Bt)-transgenic corn hybrids compared with their non-Bt counterparts

We examined nine pairs of near-isogenic hybrids of Bacillus thuringiensis (Bt) and non-Bt corn, Zea mays L., at two locations in 1999 and three locations in 2000 to compare the effects of Bt toxins on damage caused by Helicoverpa zea (Boddie) to whorl stage field corn, and ear damage at harvest, as well as yield. We found that whorl damage was less in all Bt hybrids compared with their non-Bt counterparts each year and at each location. Differences in ear damage between Bt and non-Bt hybrids, however, differed in 1999 and 2000. In 1999, only one Bt hybrid, NC+5788Bt, had less ear damage than its non-Bt counterpart at the dryland site, whereas four Bt hybrids, C8120Bt, P31B13Bt, P33VO8Bt, and NC+5788Bt, had less damage at the irrigated site. In 2000, most Bt hybrids had less ear damage than their non-Bt counterparts at each location. Differences in whorl damage did not translate into yield differences. However, variations in ear damage were partially reflected in yield differences. In 1999, P31B13Bt and P33V08Bt had higher yields than their non-Bt counterparts at both sites, whereas in 2000 all Bt hybrids had higher yields. Also, although whorl damage was not correlated with yield, ear damage was negatively correlated with yield; increasing ear damage by H. zea decreased yield for Bt and non-Bt hybrids alike. Overall, depending on location and year, each centimeter of H. zea ear damage reduced yield by between 2 and 13%.     

Indirect consequences of artificial selection on plasticity to light quality in Arabidopsis thaliana

Covariation between light quality- and photoperiod-mediated phenotypic plasticity was investigated using Arabidopsis thaliana. Three episodes of artificial selection were imposed on an index that quantified the plastic response to reduced red to far-red ratios (R:FR), with higher index values indicating greater plasticity. Relative to control lines, two high plasticity (HP) lines showed 1.6- and 2.4-fold increases in the index; low plasticity (LP) lines showed 1.4- and 1.1-fold decreases. A factorial experiment combining high and low R:FR conditions with long and short photoperiods assessed indirect consequences of selection on plasticity. Despite divergent R:FR-mediated plasticities in HP vs. LP lines, all four lines showed increases in photoperiod-mediated responses and decreases in mean leaf number. Complex relationships among trait means, plasticities and underlying mechanisms caution against generalizing about the genetic architecture of plastic traits. Partially independent developmental and evolutionary responses to R:FR and photoperiod are somewhat unsurprising, given this species' cosmopolitan nature.