Heritability, and Intra- and Inter-Generation Associations Between Tuber Yield and its Components in Potato (Solanum tuberosum L.)

The relative importance of the components of tuber yield in selection in early generations of a potato-breeding programme was studied. In seedling generation the number of tubers were more important than average tuber weight, whereas in clonal generations the average tuber weight was more important. Correlation coefficients between number of tubers and tuber yield varied from generation to generation whereas those of average tuber weight and tuber yield were more or less constant. Unlike the number of tubers, the average tuber weight of a genotype in a generation influenced its tuber yield in subsequent generations. The average tuber weight had higher heritability than the number of tubers and tuber yield.     

Further Characterization of rollC Transgenic Tetraploid Potato Clones, and Influence of Daylength and Level of rolC Expression on Yield Parameters

Tetraploid rolC transformants have been analyzed considering the level of rolC expression and yield parameters. In rolC transformants a maximum of five integrated copies of the gene were detected by Southern analysis. A relation between copy number of the rolC gene, phenotypic rolC expression and intensity of morphological alterations was established. Three experiments were performed to assess the differential effect of the rolC gene on yield and its interaction with growth factors. In the first experiment, the influence of day length on plant morphological and physiological characters was studied. The phenotype of the transgenic plants with a low rolC expression was like the control under the two day-regimes tested, while the intermediate expressing genotype showed a different reaction. In the second and third experiment, tuber yield, tuber number and weight per tuber were recorded under short and long day conditions. When grown in smaller pots of 1.15 1 volume, the control plants had the highest yield of tubers under both day lengths tested. Yield decreased with increasing rolC expression. Tuber number revealed to be genotype dependent: it was higher for low rolC expressing plants and lower for intermediate rolC transformants (Experiment 2). In the third experiment the influence of variable pot size and shape was analyzed for one clone with intermediate and two with low level of rolC expression. Remarkable differences between pots and flat boxes of the same volume were noted for tuber yield and number: Under the two conditions the control clone and the low rolC expressing genotypes gave similar tuber yield and number in both growth containers, whereas the rolC intermediate genotype yielded significantly more in flat boxes. The effect of variable hormonal levels induced in transgenic plants through prokaryotic genes are discussed with the existence of non-predictable genotype in relation to environmental interactions. It is concluded that at least the agronomic performance of potatoes transformed with these genes cannot be predicted on the basis of simple linear relationships among the expression of the gene and of the traits.     

Effect of Presprouting on Yield of Maincrop Potatoes (Solanum tuberosum L.) in Organic Farming

From 1991 to 1993 field trials at two sites (Bruchkobel and Gladbacherhof) were carried out to study the coti-tribtition of presprouting in securing the yield of main-crop potatoes (cvs. Agria. Granola. Linda and Nicola) in organic farming. In several cases presprouting diminished significantly the number of stems and tubers per plant. While in July (sample harvest) presprouting resulted in significant higher total yields with nearly all cultivars, in September (main harvest) the presprouting effect on total yield differed from year to year and partially from site to site, Presprouting reduced the percentage of undersized tubers, especially in 1992. Significant increases of the percentage of oversized tubers caused by presprouting were found especially with cv. Agria. The presprouted potatoes showed significantly higher marketable yields in 1991 at Bruchkobel (+28%), in 1992 at Bruchkobel (+ 14%) and Gladbacherhof (+ 18%) and in 1993 at Bruchkobel (+ 3%), Considerable yield increases caused by presprouting were observed when the foliage was destroyed early in the growing season by the Colorado beetle (Bruchkobel 1991) or by late blight (both sites 1992). Presprouting proved to be an important method to ensure yields in a farming system using no chemical pesticides.     

The Effect of Different Shade Levels on Growth and Tuber Yield of Sweet Potato: II. Tuber Yield

Eight sweet potato cultivars ( Ipomoea batatas Lam.) were grown under four different light regimes (0, 26, 42 and 60 % light reduction (LR)) at two experimental sites of the International Potato Center (CIP) in Peru during the 1990 and 1991 growing season. Increasing shade diminished the tuber yield of five cultivars, two showed a tolerance for slight (26 % LR) and moderate (42 % LR) shade and one had the same yield in full sunshine and slight shade. Shade mainly reduced the sink-size (tubers m ⁻²) of sweet potato and to a lesser extent the sink-strength. The growth of the plant top was hardly affected by shade; slight shade even favoured shoot development of some cultivars. The plant top was the stronger sink under shade conditions and tuber yield was not only reduced by lesser assimilate production as a whole but also by an altered assimilate partitioning.     

StGATA12对马铃薯(Solanum tuberosum)生长发育的影响

GATA转录因子是广泛存在于真核植物中的一类转录因子,它是锌指蛋白家族的成员,具有锌指结构,可以识别和特异性结合DNA序列。在调控植物开花时间、叶片延伸、花的发育以及光周期和光信号转导、叶绿素合成和碳、氮代谢调节等生物学过程中发挥重要作用。研究GATA家族的基因可以为作物增产提供一定的理论基础。本研究对转StGATA12基因的株系进行了生理生化分析,结果表明:转基因株系表现出叶面积、茎直径及单株结薯量增加的性状;叶绿素含量、淀粉含量增加;激素含量发生变化。由此可知,StGATA12转录因子在马铃薯叶绿素合成及激素平衡方面起着重要的调控作用。本研究初步阐明了StGATA12转录因子在马铃薯发育过程中的生物学功能和作用机制,丰富了植物GATA12基因的功能研究,并为培育优良的马铃薯新品种提供理论参考。     

Effect of Selection for Chip Colour on Some Economic Traits of Potatoes

The objective of this study was to investigate the effects of selection for chip colour after harvest (CH), after storage at 12. 8°C (OR), and after storage at 3°C (GO) on maturity, yield, tuber size and specific gravity. Three hybrid populations of random clones were used in this study. The parents plus seven other cultivars were also evaluated, as checks. Experiments were carried out at Benton Ridge and at Fredericton, NB, in 1991. The experimental design was an augmented block. Clones of populations were non-replicated and distributed randomly in the experiment. Check cultivars were replicated four times in a randomized complete block design. Negative responses were predicted for maturity, marketable and total yield, and tuber size (agronomic traits) and positive response for specific gravity in varying amounts for the three populations by selection for the three chip quality traits (CH, CR and CC). Therefore, selection for CH, CR and CC and the agronomic traits could not be made without some adverse effects on each other, whereas chip quality traits and specific gravity could be improved simultaneously.     

Top‐cross vs. poly‐cross as alternative to test‐cross for estimating the general combining ability in potato

Test‐crosses for estimating combining ability in potato although useful are difficult to make being labour intensive and time consuming, and due to the problem of sterility. The objective of the present study was to test methods for estimating general combining ability (GCA) of parents based on fewer matings. The GCA of 12 females estimated based on matings with specific single testers (top‐cross) and three types of bulk pollen (poly‐cross) were compared with those estimated by 72 (12 × 6) test‐crosses, using common testers in three types of matings. The study was conducted for 2 years at each of the two locations representing short‐days subtropical conditions in plains and long‐days temperate conditions in hills of India. Analysis of variance of test‐crosses showed that both general and specific combining ability effects were important for tuber yield, late blight resistance as well as general impression, the characters studied. Correlation coefficients among three types of matings showed that bulk pollen matings had poor effectiveness in predicting the GCA of the females, whereas matings with selected individual testers resulted in GCA estimates similar to those based on six testers. Thus use of top‐cross involving selected tester could substantially reduce the number of matings required for estimating the GCA. Among the six testers used, the tester CFK69.1 could estimate the GCA of the females with reasonably high accuracy both for tuber yield and general impression, and ‘Tobique’ for reaction to late blight.     

Components of Visual Selection in Early Clonal Generations of a Potato Breeding Programme

In the first two clonal generations of a potato breeding programme, clones are visually selected for ‘plant appearance’. Selection for plant appearance based on unreplicated small plots is unreliable, due to significant genotype × environment interaction and high error variance. In order to improve the selection efficiency, component traits of plant appearance were identified and the effect of selection for these components was studied. Tuber yield was found to be the principal component of plant appearance while stolon length and tuber appearance contributed significantly, but to a lesser extent. Tuber yield had a higher heritability than plant appearance. Characters determining the appearance of stolons and tubers were found to have equal or lower heritabilities than plant appearance at 80 days after planting and somewhat higher heritabilities than plant appearance at 145 days after planting. Hence, since the expected and observed selection responses of the component characters have been found to be equivalent to that of plant appearance, selection for plant appearance cannot be improved upon by separately selecting for characters like tuber yield and tuber appearance.     

植酸酶基因PhyA对陆地棉产量性状的影响

在人工控制(培养基、水培、沙培)条件下,植酸酶基因PhyA具有分解利用培养基质植酸磷、提高磷素利用效率的功能,但在田间的表现目前尚未明确。在前期完成的PhyA转基因陆地棉新材料盆栽试验基础上,将其种植在田间条件下,研究PhyA基因对棉花产量性状的影响。结果表明,部分转基因棉花新材料的单株结铃数、铃重、衣分、籽棉产量、皮棉产量与野生型对照存在显著差异,PhyA在田间条件下具有改良转基因棉花部分产量性状的能力。在此基础上,遴选出2个转PhyA棉花优良新品系G3、G2,可用作今后转植酸酶基因棉花新品种培育的基础材料。     

四川地区影响脱毒马铃薯原原种单株产量因素研究

为了提高马铃薯原原种单株产量,降低原原种生产成本,实现工厂化生产,就栽种密度、栽种时间、苗源3个主要因素对原原种单株产量进行研究。结果表明：不同扦插密度对原原种单株产量影响很大,方差分析结果达极显著,栽种密度为400苗/m2时单株产量最高,平均达到2.5粒,栽种密度过低或过高单株产量都会明显降低。不同栽种时间对原原种单株产量的影响也很大,四川地区最适栽种时间为3月15日至4月1日,过早或过迟栽种单株产量都会降低。试管苗和扦插苗的原原种单株产量相当,试管薯效果最好,平均单株产量达到3.5粒。大规模生产脱毒马铃薯原原种企业综合使用合适的栽种密度,掌握栽种时间,使用适当的苗源,是提高原原种总产量的基础。     

The Effect of Preceding Crop and Pre-Sprouting on Crop Growth, N Use and Tuber Yield of Maincrop Potatoes for Processing Under Conditions of N Stress

Factorial field trials were carried out on an experimental farm near Kassel, Germany, in two consecutive seasons (2003 and 2004) in order to examine the impact of leguminous and cereal preceding crops (i) on soil N availability under subsequent potatoes and (ii) the effect of preceding crop and pre‐sprouting of seed tubers on crop development, N uptake, N utilization efficiency and total and size‐graded tuber yields relevant for processing into either crisps or French fries. In addition, an approach to analyse complex field experiments using mixed models is discussed. Soil mineralized nitrate‐N at emergence of the potato crop was affected by the preceding crop and was highest when potatoes followed peas, while the short‐term alfalfa/grass/clover ley appeared too sensitive to environmental conditions in the preceding cropping season, and its efficiency in terms of N supply may be hard to predict. Pre‐sprouting advanced crop development and dry matter accumulation of the canopy, translocation of assimilates and N from canopy into tubers and allowed an increased N utilization efficiency. The positive effect of pre‐sprouting on total tuber yield was compensated up to the final harvest, but a higher percentage of marketable tuber yield for French fries (>50 mm) was found independently of the date of harvest. An increasing N supply (after peas and a following catch crop) may be efficient in terms of higher yields of the marketable size‐grades (40–65 mm) for crisps, but increase oversized tuber yields in seasons not affected by Phytophthora infestans. Average tuber fresh weight responded consistently and positively to seed‐tuber preparation (pre‐sprouting), cultivar (cv. Agria) and an increased N supply (after peas).     

Transformation of Diploid and Tetraploid Potato Clones with the rol C Gene of Agrobacterium rhizogenes and Characterization of Transgenic Plants

Diploid and tetraploid potato clones were transformed with the rol C gene from Agrobacterium rhizogenes under the control of the cauliflower-35-S promoter. Parameters proper to the sink and source attributes and hormone treatments have been considered to study the effect of the gene on yield physiology of the potato plant. The expression of the rol C gene in diploid and tetraploid potato lines induced drastic developmental abnormalities like dwarfism and increased tillering. Hormonal treatments revealed a different behavior of rol C transformams and controls. This supports the conclusion that the gene product of the ml C gene interacts with the hormonal status of the plant. Grafting experiments showed the non-ditfusable nature of rol C gene product. Tuberization was studied in-vitro and in-planta. Relevant differences in tuber shape and eye number were noted between rol C transfonnams and controls. Tuber yields in-planta in greenhouse or in growth chamber resulted higher in the controls; a significant increased number of tubers per plant was found, however, in both diploid and tetraploid rol C transformants. The effect of the rol C gene was apparently too drastic for diploid and tetraploid potatoes; weaker and tissue specific promoters may be necessary to induce only those modifications which are wanted for this crop. The experiments nevertheless proved that one single gene was capable in potato to affect substantially the manifestation of vieldmg attributes.     

Widespread introgression of Solatium phureja DNA in potato (S. tuberosum) dihaploids

Dihaploids were assumed to be of parthenogenic origin but cv. ‘Pentland Crown’ dihaploids produced at the Scottish Crop Research Institute (SCRI), Dundee, Scotland, are known to contain DNA from the S. phureja dihaploid inducer. This study investigates whether inducer DNA occurs in dihaploids of cultivars ‘Aminca’, ‘Brio’, ‘Lizen’ and ‘Sirtema’, produced at INRA, Ploudaniel, France. Two microsatellite markers and five simple sequence repeat 5′-anchored polymerase chain reaction (PCR) primers were used to generate markers. Markers originating from the dihaploid inducer were detected in 13 of the 19 INRA dihaploids and in some dihaploids from each cultivar. Greater introgression occurred in ‘Lizen’ dihaploids than in ‘Brio’ dihaploids, suggesting that the female (S. tuberosum) parent influences introgression. The percentage of INRA dihaploids containing inducer DNA was similar to that for ‘Pentland Crown’ dihaploids (c. 65%). The micro-satellite markers provided the first evidence of the transfer of specific, potentially useful, genes from the inducer to the dihaploid offspring. Interspecific introgression during dihaploid induction is more widespread than previously thought and researchers should be aware that it may influence the results of research using dihaploids.     

种茎对多花黄精产量和药用品质的影响

针对目前国内多花黄精种茎无标准和用种不规范的现状,研究多花黄精种茎规格、年龄对产量及药用品质的影响,旨在为多花黄精科学选种用种提供理论依据.采用双因素随机区组设计,主因素为规格,副因素为年龄,以多花黄精种茎的芽头数、茎长、茎径和茎质量为指标,采用K-means聚类法将种茎分成3个规格、3个年龄,通过调查出苗率、单株产量...     

The Use of RFLPs (Restriction Fragment Length Polymorphisms) Detects Germplasm Introgressions from Wild Species into Potato (Solanum tuberosum ssp. tuberosum) Breeding Lines

The germplasm of the potato (S. tuberosum ssp. tuberosum) has been modified since the beginning of this century by breeders who introgressed important agronomic traits, for example disease resistance genes, from several wild and cultivated Solanum species of the Americas. In this paper we show that the Rflp analysis of potato-breeding material can be used to detect chromosomal regions descended from more-distantly related Solanum species. The Rflp patterns of individuals of ten Solanum species, ten breeding lines of S. tuberosum ssp. tuberosum and the cultivated variety ‘Bintje’ were analyzed. Rflp data for each of eight single loci of known genomic position were used for the computation of locus-specific phenograms by distance matrix methods. Several of the potato-breeding lines deviated clearly from the clustered species S. tuberosum, S. stenotomum and S. canasense for one or more of the loci considered. These deviations indicated the presence of “exotic” germplasm at a particular locus. The possibility of detecting such germplasm has implications for mapping the agronomic traits for which the wild species were introgressed and which may still be linked to “foreign” chromosome fragments.     

外源类甜蛋白基因在马铃薯中的表达

将“津引薯８号”马铃薯薄版和含有ＣaMV35S启动子控制的类甜蛋白（ＴＬＰ）基因与紧密连锁的Ｕbiquitin启动子控制的bar标记基因的农植菌双元表达域体进行共培养。切下马铃薯薄片表面产生的幼芽,用含有除草剂bialaphos的ＭＳ培养其进行初步筛选。当获得的生根抗性芽生长成株后用ＴＬＰ蛋白抗体和ＴＬＰ基因特异引我对成株进行间接ＥＬＩＳＡ检测和ＰＣＲ检测。两种检测结果一致率为９０％,推断以bar基因为筛选标记、紧密连锁 的外源类甜蛋白基因已经进入马铃薯基因组并利以表达。     

转基因抗虫棉产量性状的遗传效应及其杂种优势分析

采用加性-显性与环境互作的遗传模型,分析了9个亲本和36个F1的皮棉产量、单株铃数、铃重和衣分的两年资料,估算了转基因抗虫棉各项遗传方差和成对性状间各项遗传效应的相关性.结果表明,转基因抗虫棉的产量性状受加性和显性效应共同控制,皮棉产量、铃重和衣分都以基因的显性效应为主,而单株铃数是以加性效应为主,单株铃数和衣分还具有基因与环境互作效应.遗传相关分析表明,转基因抗虫棉的皮棉产量与单株铃数的基因型和表现型相关系数都比较大而且比较接近;皮棉产量与单株铃数、铃重和衣分的加性相关系数都达到极显著水平,而且皮棉产量与单株铃数、衣分的数值比较大.利用亲本和F1的资料预测了F2基因型值和杂种优势,结果表明,转基因抗虫棉F2的皮棉产量、单株铃数、铃重和衣分的群体平均优势分别为4.0%、5.1%、-1.3%和3.2%,群体超亲优势分别为-7.3%、-6.0%、-4.2%和-0.5%.     

转基因甘蓝型油菜向其近缘种的基因漂移之研究进展

从甘蓝型油菜的生活周期出发,概述了甘蓝型油菜及其近缘种的开花习性、甘蓝型油菜与其近缘种的杂交亲和性、杂种及其回交后代的育性和适应性,评价了在中国环境条件下甘蓝型油菜中的外源基因向其近缘种漂移而导致生态风险的可能性。认为在中国环境条件下,转基因甘蓝型油菜向其野生杂草近缘种的基因漂移风险较小,而如何防止转基因向白菜型油菜（Brassica rapa）和芥菜型油菜（B.juncea）转移应作为中国转基因甘蓝型油菜基因基因漂移风险控制的关键。     

外源Bt基因对棉花产量性状及抗虫性的影响

本文在介绍转基因抗虫棉研究现状的基础上，综述了外源Ｂｔ基因对棉花产量性状及抗虫性影响的研究进展；并指出了Ｂｔ抗虫棉当前存在的几个问题，提出了提高转基因抗虫棉抗虫性和使用寿命的几种方法。     

不同种植模式对玉米产量与农艺性状影响分析

为了探明玉米种植的最优方式,试验采用裂区设计,研究不同耕作方式、种植密度及施N肥量对玉米的产量和农艺性状的影响。结果表明：不同的耕作方式和不同施N肥量玉米的产量差异均达显著水平,不同种植密度的玉米产量差异不显著。在各组合中,以平作耕作方式、密度67500株/hm2、施N量为112.5 kg/hm2,玉米产量最高;耕作方式对玉米棒三叶叶面积和株高影响差异达显著水平,对最大叶面积指数和茎粗影响差异不显著;密度对玉米最大叶面积指数、棒三叶叶面积和茎粗影响差异显著,对株高影响差异不显著;施氮与不施氮之间最大叶面积指数、棒三叶叶面积、茎粗和株高差异显著。