花生籽粒比重与生态特性的研究

不同花生品种籽粒比重有差异，花生籽粒比重和生育日数、结荚日数呈正相关，和开花与结荚日数二者比值呈显著负相关，结荚日数长有利于增加花生籽粒比重。在花生营养生长时期长日照、高温、较小温差，生殖生长时期短日照、低温和较大温差有利于干物质积累。花生籽粒比重的变化与品种的遗传和干物质积累时的气候因素有关。     

Effect of irrigation applied at different growth stages and length of irrigation period on quality characters of potato tubers

Summary Potatoes were irrigated at three growth stages: (1) planting-stolon initiation. (2) stolon initiation-tuber bulking, and (3) tuber bulking, when available soil water dropped to 25%, 50% and 75%, bringing it up to field capacity; and irrigation ceased 0, 10 and 20 days before maturity. Significant increases in specific gravity, dry matter, starch content, chip yield and significant decreases in protein content and oil absorption rate of chips were observed due to the frequent irrigation at growth stages 1 and 2. No significant effect on chip colour was attributed to irrigation during the early growth stages. Frequent irrigations at the final growth stage were found to have deleterious effects on specific gravity, dry matter, starch content and chip yield especially when irrigation continued until maturity.     

Influence of intercellular space differences due to variety and storage upon tuber specific gravity-dry matter relationship

At each of two locations in two years, five varieties of potatoes were examined for specific gravity—intercellular space relationships. At harvest intercellular space differred consistently among varieties and decreased during two months' storage at 40 F. Changes in weight, volume, and intercellular space were used to explain that changes in tuber specific gravity may or may not reflect changes in dry matter content and that differences and changes in intercellular space are of sufficient magnitude to account for most of the discrepancies between recently published regressions of dry matter on specific gravity developed without correction for intercellular space. A coordinated study is proposed to establish the correctness of this postulation. Estimation of dry matter content of white potatoes from specific gravity determinations is a widely accepted practice. The accuracy of the estimation has been questioned because of the relatively large error of estimation (±1.5 to 2%) usually encountered (24), the wide divergence of regressions (1, 6, 15, 16, 18, 19, 23), and the frequency with which discrepancies have been noted between specific gravity and quality (14). Recent recommendations call for “Improved accuracy in the quick estimation of solids either by specific gravity or other means” and clarification of the “effect of temperature and period of storage on changes in ... specific gravity” (25). The tests reported here were undertaken to obtain corroborating evidence for the estimation of dry matter content of sweet potatoes from root specific gravity after correction for intercellular space (IS), (8, 12). Sweet potatoes, as well as several other commodities, contain relatively large amounts of IS (8, 11) but when this is accounted for, a reasonably consistent relationship exists that appears to be nearly identical to the regression for the specific gravity of sucrose solutions (8). The work with sweet potatoes showed that 1 ml of IS produced a buoyancy equivalent to the weight in water of 2.38 g of dry matter (12). Although white potatoes contain relatively small amounts of IS on the average, amounts of 1% (1ml/100ml) and more have been reported (2, 8, 15, 16). Nissen, in Denmark, reported that varieties differed in IS and that for greatest accuracy the IS should be accounted for (15, 16). Most workers in the United States, however, have ignored the influence of IS upon the accuracy of the methol of estimating dry matter content from tuber specific gravity, although several have speculated that IS contributed to variation in this relationship (1, 18). The tests reported here indicate that varieties may differ with reasonable consistency in IS at harvest in much the same manner as sweet potatoes (17), and that these differences and changes in IS during storage may be large enough to account for most of the discrepancies observed in the relationship between tuber specific gravity and dry matter content.     

Nematicides induced changes in the chemical constituents of potato tubers

Changes in the chemical constituents of potato tubers grown under different concentrations of 3 synthetic organic nematicides (carbofuran, aldicarb and phorate) and a natural plant product (sawdust) were investigated. There were no significant differences in the specific gravity, dry matter and starch content of tubers from different treatments. A significant increase in the content of non-reducing and total sugars was observed in all the treatments. Nematicidal treatments had significant effects on reducing sugars, true protein, free amino acids, orthodihydroxy phenols, beta-carotene and ascorbic acid. Application of nematicides reduced the content of total phenolic compounds which is a desirable change from a processing viewpoint. Potatoes grown under different nematicidal treatments can be processed into chips and French fries as they contain permissible levels of reducing sugars required for these forms of processing.     

Specific gravity and dry matter content of potato

Summary Data obtained from 516 pairs of specific gravity and dry matter determinations were used to derive a relationship for estimation of dry matter content of potatoes grown in India.     

The relationship between specific gravity and percentage dry matter in potato tubers

Specific gravity and percentage dry matter were determined for 1269 potato samples taken over a period of six years. The correlation coefficient between these properties over the whole material was 0.912 and the regression equation was: % dry matter = ?217.2 + 221.2 (specific gravity). When the material was broken down into smaller, logically defined groups, such as a single cultivar, regression lines often deviated from this general line, although in most cases the correlation coefficients were still quite high. This means that the quantitative relationship between specific gravity and dry matter content was not sufficiently stable to serve as a general measure of prediction under all conditions. It seems probable that various production areas of the United States will have to develop the line which is best suited to their conditions, and that some cultivars may require separate lines.     

Genotypic stability analysis of eight potato varieties tested in a series of ten trials

Genotypic stability analyses were carried out for five characteristics of eight potato varieties which had been tested in the New Brunswick Variety Trial in the past ten years, 1961–1970. Special attention was paid to three economic traits, i.e., marketable yield, specific gravity and dry matter yield. General adaptability was defined in this paper as having average genotypic stability and above-average mean performance. Kennebec showed the best general adaptability of marketable yield, Hunter for specific gravity and Netted Gem dry matter yield. No variety was ranked at the top for both marketable tuber yield and specific gravity. Some implications of this study on potato breeding are discussed.     

Evaluation of potato cooking quality in Argentina

Cooking quality of mature tubers was assessed for ten Argentine potato cultivars, two cultivars of foreign origin and three advanced clones. Specific gravity, dry matter and starch content, as well as quality of boiled potatoes and chips were determined Pampeana INTA had the highest dry matter content with 21.8 percent and would appear to be a very good cultivar for dehydrated products. The lowest dry matter values were obtained for three of the four most widely planted cultivars: Spunta, Bonaerense La Ballenera and Kennebec Kennebec demonstrated its good quality for chipping with a score of 6.9 points. Primicia INTA and Sureña INTA with high dry matter content and good features for chipping can also be used to produce chips Breeding under high temperatures during tuberization has proven to be a successful strategy in developing cultivars that are superior in dry matter contents to the cultivars currently imported from the northern hemisphere     

The relation between specific gravity and dry matter content of potato tubers

The theoretical basis of the relationship between the percentage of dry matter in a potato and its specific gravity is examined. The relationship is hyperbolic but, for values of dry matter percentage usually encountered with potatoes, a linear approximation is adequate. However the specific gravity of a tuber depends not only on the percentage of dry matter in it but also on the density of the dry matter and the percentage of air in the tissue. Thus dry matter percentages estimated from specific gravities may be in error if it is assumed that the linear approximation is constant.     

Relations between specific gravity,dry matter content and starch content of potatoes

Summary Published relations between specific gravity, dry matter content and starch content are summarized in the form of regression equations and a diagram. It is suggested that, for the potato literature, uniformity of presentation of results and of conversion equations used would be desirable.     

Dry matter content and mineral composition of potatoes grown in Cyprus

Summary The specific gravity and dry matter content of 193 tuber samples (cultivars: Arran Banner, Spunta, Up-to-Date, Cara) from crops grown at Kokkinochoria, the major potato growing area of Cyprus, were related to each other as follows: Dry matter (%)=−269.59+268.24×specific gravity. This regression accounted for 82.4% of the variation; the fiducial limits (P<0.05) for single determinations of specific gravity were±1.54 percentage units. The mineral contents of the tubers were similar to those reported in other countries.     

Starch and dry matter content of Netted Gem in relation to French fry texture

Studies were made on the relation of French-fry texture to solids content and to starch granule size in stored Netted Gem potatoes. Texture as evaluated both by a sensory panel and by an objective method was positively correlated with the percentages of starch granules in the 31–44 and 22–31 micron ranges. The usual positive correlations of texture with starch content, dry matter content, and specific gravity were in evidence. In limited trials, greater starch viscosiy and swelling power were associated with poorer texture. Heating time required to reach maximum viscosity was also related to texture, the longer heating times being associated with better texture.     

A common regression for estimating dry-matter content of carbohydrate-containing commodities from specific gravity

For nine commodities that consist primarily of carbohydrates and water, corrections for intercellular space permit highly significant correlations between percent dry matter and corrected specific gravity. Drymatter contents for all commodities ranged from about 3 to 36%. Throughout this range the commodity mean values fall approximately on the regression line for specific gravity of sucrose solutions on dry matter percentage of the solutions, and the individual regressions often nearly coincide with the sucrose regression. It is suggested that, when intercellular space is accounted for, the sucrose regression is representative of commodities that consist primarily of water and carbohydrates.     

Relationship of specific gravity to sugar accumulation in stored Norgold and Russet Burbank potatoes

Studies were made on the influence of growing season and low fertility on reducing sugar accumulation in storage of the stem and bud portions of Russet Burbank and Norgold Russet potatoes separated into different specific gravity groups. The stem portion of Russet Burbank had a significantly different intercept and slope of regression line (between specific gravity and reducing sugar accumulation) than the bud portions of the same tubers indicating higher reducing sugar accumulation in the stem portion as well as differences in behavior as to amount accumulated at the different specific gravity levels. No significant difference in sugar content or behavior at the different specific gravity levels was obtained between stem and bud portions of Norgold Russet. Growing season did not cause significant differences in total sugar content or slope of the regression lines within the stem or bud portions of Russet Burbank. Low fertility level resulted in significantly higher sugar accumulation in the stem portion of Russet Burbank as compared to adequate fertility and there was also a trend toward less influence of specific gravity on sugar accumulation at the lower fertility level. Low specific gravity Russet Burbank potatoes tended to be more variable in sugar accumulation from year to year and also had wider differences in sugar accumulation between stem and bud portions than high specific gravity potatoes.     

Specific Gravity, Dry Matter Concentration, pH, and Crisp-making Potential of Ethiopian Potato (Solanum tuberosum L.) Cultivars as Influenced by Growing Environment and Length of Storage Under Ambient Conditions

A study was conducted to investigate the influence of genotype, growing environment and storage period on postharvest quality of seven released potato cultivars grown at Adet (2240 masl), Chilga (2270 masl), and Dabat (2620 masl), northwest Ethiopia in 2006. Cured tubers of each cultivar from each location were stored at ambient conditions for 8 weeks in a locally constructed dark room in Adet, the location with the highest temperatures. The quality of the tubers and the crisps prepared from them was evaluated at weekly intervals. Tubers from cvs Jalenie, Guassa, and Zengena had a high specific gravity (1.088–1.094) and dry matter percentage (26.2–27.1%) when grown in Dabat and Chilga, and a lower specific gravity (1.064–1.072) and dry matter percentage (22.3-22.7%) when grown in Adet. These cultivars produced crisps with a taste value of 8 (like very much) when grown in Chilga and Dabat and of almost 7 (like moderately) when grown in Adet. There was a progressive reduction in specific gravity, dry matter percentage, and taste of crisps with increase in storage time. Cultivars with higher dry matter concentration maintained a better quality than cultivars with a lower dry matter concentration. Across growing locations and cultivars, 57% of the crisps samples were white to cream colored, 33.3% light tan and 9.5% dark tan after 1 week of storage, whereas after 6 weeks of storage none of the cultivars produced white cream colored crisps. It is reasonable to conclude that cvs Jalenie, Guassa, and Zengena can produce tubers with a high dry matter percentage under Chilga and Dabat conditions, from which acceptable crisps can be prepared from tubers stored up to 6 weeks under ambient conditions.     

大豆子粒比重与生态特点的研究

不同纬度、不同品种类型大豆子粒比重有差异。随着纬度的增加 ,春大豆子粒比重增加。同一产地大豆子粒比重春豆 <夏、秋豆 ;但变异系数春豆 >夏、秋豆。大粒子粒比重不如小粒种子 ,大豆百粒重、体积和比重均呈显著和不显著的负相关。大豆子粒比重和生育日数、结荚日数呈正相关和开花与结荚日数二者比值呈显著的负相关 ,缓慢的鼓粒速度有利于增加大豆比重。在大豆生育阶段子粒比重和日照、温度关系由显著的正相关演变为极显著的负相关 ,和温差由负相关演变为极显著的正相关。在大豆营养生长时期长日照、高温、较小温差 ,在生殖时期短日照、较低温和大的温差有利大豆干物质积累。大豆子粒比重的变化与品种的遗传型本身和物质积累时的气候因素有关。     

Shear press determinations of the raw product as a possible tool for quality measurement of potatoes

Texture determinations were made with a Food Technology Corporation shear press on Russet Burbank and Norgold tubers as they grew and developed from July 1 until October 15, 1970. Shear force reading increased as Russet Burbank tubers grew and increased in dry matter content. However, no increase in shear force was obtained with growth and development of the Norgold variety. Tubers harvested in the Fall were placed in 48 F storage and separated into specific gravity groups in increments of 0.005 with a brine solution. As specific gravity of the Russet Burbank variety increased, shear force readings also increased. Shear force of the Norgold Russet did not change with specific gravity changes. A very high correlation was obtained between raw shear force readings of specific gravity groups (Russet Burbank) and processed frozen french, fries of the same lots which were finish fried and shear force readings made within 3 minutes after removal from the fryer. Again, the correlation between raw shear force readings and finish fry readings of Norgold Russet was very poor, although the finish fry product readings increased as specific gravity increased.     

广东凤凰单枞茶树品种（系）叶片主要性状的种间差异和地域变异研究

对广东潮州凤凰山区不同地域的50种凤凰单枞茶树品系的叶缘锯齿数、侧脉数、叶形、叶绿素含量、叶面积（LA）、叶干物质量（LDMC）、比叶面积（SLA）等叶片形态和功能性状进行了比较研究,并对不同海拔地带的12种凤凰单枞茶树主要叶片性状进行了地域变异研究。结果显示,50种凤凰茶树叶片形状为卵圆形至长卵形（叶形指数1.99~3.16）,叶绿素含量平均为64.348（SPAD测定读数）,平均单叶面积24.237 cm²,叶干物质含量40.65%,比叶面积80.947 cm²·g^-1。50种凤凰单枞茶树的叶面积变异最大（变异系数为21.12%）,比叶面积变异次之（18.3%）,叶形状（9.8%）和叶绿素含量（10.4%）变异较小,叶干物质含量变异最小（5.9%）;南馥茶园的兰花香、柚花香、宋种、八仙、桂花香、夜来香、蜜兰香等品系叶片单位面积合成的有机物质较多,对外界资源有效利用率较高;南馥茶园的玉兰香、水仙、姜花香、杨梅叶和区山塘茶园的玉兰香等品系叶片单位面积合成的有机物较少,对外界资源有效利用率较低;高海拔地带的部分凤凰单枞茶树具有叶面积大、叶干物质含量少、比叶面积大、叶绿素含量多的趋势,表明种植地域的海拔对凤凰单枞茶树叶片性状有较大影响。     

Chemical composition of potatoes. VII Relationship of the free amino acid concentrations to specific gravity and storage time

Prior to storage, Maine-grown Katahdin potatoes were sorted into five specific gravity classes. Samples of three classes (high, intermediate, and low) were stored in individual boxes at 38 F for eight months, 45 F for one month, and 50 F for one month. New York-grown Katahdins were sorted into specific gravity classes periodically after removal from storage. Both lots were analyzed periodically for free amino acids (including the amides). In general, an inverse relationship was found between total solids and free amino acids calculated on a dry weight basis in Maine-grown and New York-grown Katahdin potatoes. In most cases little difference was found on the fresh-weight basis. Changes in the amino acids during storage were quite random. The differences found in the amino acid values between samples due to sorting for specific gravity before and after placing in storage were minor.     

OAC Ruby Gold: A new red-skinned yellow fleshed table potato cultivar

OAC Ruby Gold is a new potato cultivar with red skin and yellow flesh. Tubers are oblong in shape. When evaluated over three years at three sites in Ontario, it had higher specific gravity and culinary quality than Chieftain. OAC Ruby Gold has the same maturity and slightly lower yield than Chieftain. It is recommended for fresh market use in Ontario.