The Effect of Nitrogen Fertilization and Population Density of the Field Bean (Vicia faba L. minor) of Indeterminate and Determinate Growth Habit on the Symbiosis with Root Nodule Bacteria and on the Seed Yield

Field beans of indeterminate (cv. Nadwiślański) and determinate (cv. Tibo) growth habits were grown on field plots with a density of 20, 40 and 80 plants m⁻² at two levels of nitrogen fertilization: low (20 kg N ha⁻¹) and very high (150 kg N ha⁻¹). At the phase of intense pod growth the number and the dry matter weight of root nodules as well as their nitrogenase activity and some features of the plants growth were determined, and in the period of ripeness the components of seed yield were established.
It was found that increased density of sowing as well as the high level of nitrogen fertilization inhibited the growth and development of root nodules and limited their nitrogenase activity in both cultivars. Plants of both varieties were characterized by a similar potential of forming the root nodules, however, in plants of the cv. Tibo the nitrogenase activity of nodules was much lower than in the cv. Nadwiślański.
Increased population density of the plants has in both varieties given increased seed yield when calculated per m² of the soil, compensating in excess the depression of the seed yield from one plant. Such compensation did not occur in the case of the depression of nitrogen fixation under intense nitrogen fertilization.     

The Effect of Detopping the Field Bean Plants (Vicia faba L. minor) and Lack of the Pod Setting on the Symbiosis with Root Nodule Bacteria

The plants of field bean var. Nadwiślaνski were detopped after about 1 month since the beginning of flowering and after that all flower buds were removed from some plants. The effect of a change in the trophic balance on the setting and subsequent growth of root nodules was studied.
The removal of pods had the greater effect on the increase in the weight of the remaining organs than the detopping of plants. Detopping retarded the ageing of the plants and delayed the phase of the greatest reduction of the number of pods. The detopping of plants revealed their considerable compensative possibilities in terms of production of the pod weight and the potential of leaves for biomass production. The data obtained indicate that plant detopping may disturb the root–bacteria exchange of signals, necessary to initiate the nodule development, while the further growth of nodules depends, above all, on the amount of available photosynthates.
A very high correlation between the dry weight of the whole plant to the dry weight of leaves ratio and the weight of nodules was observed. It proves the importance of the trophic balance of the plant for the root nodule weight production.     

Influence of Soil Drought on Plant Growth, Assimilation and Dissimilation of CO2 and Accumulation of Photosynthates in Field Bean (Vicia faba L. minor) During Pod Formation and Rapid Pod Growth

Field bean planes cultivar Nadwiślański were submitted to soil drought (30 % of field soil water capacity) for 5 days at the stage of pod formation (A) and of rapid pod growth (B) and then exposed for 20 minutes to ¹⁴CO₂. Radioactivity of leaves, stems, roots, and pods or pod shells and seeds was measured 1, 5, 24 and 48 hours after exposition.
In both stages soil drought reduced by about five times total CO₂ assimilation, mainly owing to lower activity of the photosynthetic apparatus and also, though less so, to reduced leaf growth. Photosynthetic activity referred to the dry weight of the leaves dropped to 22-35% of controls. Accumulation of photosynthetates in generative organs was much less depressed than ¹⁴CO₂ assimilation. 48 hours after exposition to ¹⁴CO₂ of drought treated plants, the contents of ¹⁴C of pods in phase A, and seeds in phase B, amounted to respectively 24% and 36% of assimilated ¹⁴C and equalled 91.5% and 74% of the corresponding values for controls.
The progressive decline of radioactivity in leaves and stems after ¹⁴CO₂ exposition was distinctly correlated to the rise of radioactivity of generative organs both in soil drought treated plants and in controls. Slightly lower values of correlation coefficients in drought treated plants may indicate impairment under drought conditions of synchronization in processes of unloading and accumulation of assimilates.
In plants drought treated in phase A the ability to dissimilate ¹⁴C was reduced to about 59% of that in controls, but when drought was applied in phase B, dissimilation rate was about three times as high.     

Effect of Completion of Vernalization on Generative Development of Winter Rape (Brassica napus L. var. oleifera) Plants

Germinating seeds and young plants of winter rape var. Górczañski were vernalized for 56–63 days under conditions of 9-hour day, at the temperature 2 and 5 °C and in continuous darkness at the temperature 2 °C. After vernalization the plants grew under conditions enabling to complete vernalization: in a glass-house at the temperature day/night 15/10 °C and in semi natural conditions of open vegetation hall in the period from June till August. After sub-optimal vernalization further growth of the plants at lowered temperature increased its effectiveness (completion of vernalization). Depending on the degree of the vernalization of the plants the completion of their vernalization was both obligatory, i.e. conditioning the acquisition of the ability of generative development, and facultative i.e. accelerating this development. It has been demonstrated that the population of plants of the examined variety is strongly differentiated not only with respect of vernalization requirements in the particular plants, but also what regards the effectiveness of vernalization completion. New observations have been made indicating that the mechanisms controlling the successive phases of generative development, i.e. phase of forming flower buds and the flowering phase are not identical which may be interpreted as indicating that the "flowering factor" is polymorphous.     

Induction of Generative Development of Winter Rape (Brassica napus L. var. oleifera) in Relation to Vernalization Conditions and Age of Vernalized Plants

Germinating seeds and young winter rape plants were vernalized 56–63 days at 5 or 2°C under nine-hour days or in darkness. The highest percentage of generative plants and the most rapid flowering were obtained following the vernalization of young seedlings and germinating seed under conditions of nine-hour day, at 5°C. The least effective induction of generative development followed the vernalization at 2°C in continuous darkness. The vegetation period from the end of vernalization till the beginning of flowering was the shortest when four-week-old plants were vernalized under conditions of nine-hour day, yet the vegetation period from the beginning of germination to flowering was the shortest when seed germinating under conditions of nine-hour day were vernalized. The period was extending as older plants were being vernalized. Data indicating that the optimal temperature for vernalization of older plants is higher than for germinating seed and young seedlings were obtained.     

Responses to Selection for Root Dimension in a South European Variety of Perennial Ryegrass)*

The objective of the study was to determine the effect of selection for large root dimension on root and shoot characteristics of an Italian variety of Lolium perenne L. (cv. ‘Vejo’). Two cycles of recurrent restricted phenotypic selection (RRPS) were carried out in 1983 and 1984 at Perugia (Italy). In each cycle, 20 out of 1,500 plants were selected and intercrossed under isolation. In 1985, 120 plants from‘Vejo selected’ and an equal number of plants from‘Vejo’ initial seed-lot were grown hydroponically for 92 days; at the end of the experiment, the plants were measured for their number of leaves and stems, leaf length, length of the longest root, root volume and shoot and root dry weight. Sufficient genetic variability existed among plants of cv. ‘Vejo’ to allow highly significant responses to selection for root dimension (+25 % in root length, +39 % in root volume, + 67 % in root dry weight and +31 % in root: shoot dry weight ratio). Furthermore, two cycles of RRPS for root dimension did not show negative responses of the above-ground parts of the plant.     

Observations of Effects of Partial Vernalization in Winter Rape Plants Grafted Onto Generative Stock

Winter rape plants vernalized under natural conditions were used as stock for grafting apical and subapical parts of rape seedlings vernalized at 5 °C in light during different periods ranging from 0 to 10 weeks. Acceleration of generative development in both kinds of grafts occurred already after 3 weeks of their vernalization, i.e. after cold treatment of insufficient length to induce flowering in plants developing independently. Effectiveness of vernalization — measured by acceleration of flowering in grafts was highest from 3rd to 5th week of cold treatment and then it declined. Processes occurring during an early stage of vernalization, though insufficient to allow independent generative development, become manifest in grafts made on vernalized stock. This allows investigations of very early stages of vernalization processes inaccessible to observation by other methods.     

Photoperiod and vernalization response of wheat under controlled environment and field conditions

Characterization of large numbers of breeding lines for vernalization and photoperiod response in wheat is needed to enhance adaptation. A total of 20 wheat lines were evaluated for response to vernalization and photoperiod under two controlled environments and high ambient air temperatures under field conditions. Vernalized and non-vernalized seedlings were transplanted into pots and placed in three photoperiod (8, 12 and 16 h of light) cabinets, in the greenhouse or in growth chambers. Days to anthesis decreased with increasing photoperiod. Vernalized plants flowered earlier than non-vernalized. There was a significant correlation between days to anthesis in the greenhouse and the growth chamber (r = 0.88, P < 0.001). Basal vegetative period, effect of vernalization and photoperiod from the two screening techniques were positively correlated with each other. Growth habit, vernalization requirement and heading date in the field were highly correlated with the main effect of vernalization in the two controlled environments. The results indicate that selection for vernalization response in a large number of genotypes can be achieved under high ambient air temperatures in the field and the selected material can subsequently be screened for photoperiod response under greenhouse conditions.     

Effect of embryo age and culture media on plant growth and vernalization response in winter wheat

Summary Embryo age and composition of nutrient medium affected plant growth and response to vernalization in winter wheat (Triticum aestivum L.). Root and shoot development was more in older than in younger excised embryos, and more in a medium without kinetin than in one with kinetin. Kinetin (2 mg/l) in the medium did not accelerate vernalization, probably because it tended to inhibit seedling and plant growth.Embryo age and media did not completely replace vernalization. Twenty- and 16-day-old embryos responded by flowering after 4 weeks of vernalization. Among plants raised on a standard medium from 20-day-old embryos and vernalized for 4 weeks, 84.2% flowered by or before 50 days after transplanting. Time from embryo culture to heading for 20-day-old embryos with-4-week vernalization averaged 84.6 days. Immature embryos (16–20 days old) needed only 4 weeks of vernalization compared to 6 weeks for mature embryos. Excised embryos could be vernalized as efficiently as seedlings raised by embryo culture. Embryo culture at 16–20 days after anthesis coupled with 4-week cold treatment shortens generation time of winter wheat by about 40 days.Contribution No. 82-131-j, Department of Plant Pathology, Kansas Agricultural Experiment Station, Manhattan, KS 66506, USA.     

Effect of vernalization and photoperiod on flax flowering time

Vernalization and photoperiodism are two important physiological processes related to yield of many cool-season annual crops. The flowering response of 20 flax (Linum usitatissimum L.) genotypes to two vernalization regimes (vernalized and unvernalized) and two photoperiod treatments (10 and 14 h) was evaluated in a growth chamber study in 2010 and 2011. The results suggest that photoperiod, vernalization, and genotype all had an effect on earliness as measured by days to anthesis. Unlike flax grown in the Upper US Midwest and Canada, Texas flax is grown in the fall due to high spring and summer temperatures. Genotype interaction was observed with both vernalization and photoperiod. Specifically, flax genotypes from Texas (winter type) were sensitive to both vernalization and photoperiods for flowering. Texas genotypes delayed anthesis for 7 days or more in unvernalized seedlings, whereas flowering time of most other spring grown flax genotypes was unaffected by the vernalization treatments. Texas genotypes also delayed anthesis for 12 days or more under vernalized and short day conditions, whereas most other genotypes were not influenced by photoperiodism in vernalized seedlings. The selection for vernalization and photoperiodic sensitivity in Texas genotypes and introgression of these traits into recently adapted spring grown genotypes is needed for development of high yielding flax genotypes for southern Great Plains production areas.     

Vernalization of immature embryos of winter wheat genotypes

Summary The effect of direct vernalization of immature embryos on flowering was studied in six winter wheat genotypes. Fourteen-, 17-, and 20-day-old embryos were excised and vernalized for 0–6 weeks on synthetic medium during a conditioning period. Percent germination of embryos was high (overall 96.1%), and free from genotypic effects. Genotypes differed for flowering in response to cold treatment of excised embryos. Embryo vernalization was as effective as or more than conventional vernalization (control, seedling vernalization for 6 weeks). Seventeen-day-old embryos were the most responsive to vernalization. With a 5-week vernalization of 17-day-old embryos, the percentage of plants anthesed was higher than those from 14-and 20-day-old embryos. For 17-day-old embryos vernalized for 5 weeks, the mean number of days from culture to anthesis was less than that of 6 week vernalization, less than that of 14- and 20-day-old embryos, and less than controls.Purdue Univ., Agronomy Dept., W. Lafayette, IN 47907, USA.     

A vernalization protocol for obtaining progenies from regenerated and transgenic tall fescue plants

Tall fescue is an important outcrossing forage and turf grass species that requires vernalization to flower. A reproducible protocol was developed for vernalization of regenerated, transgenic and seed‐derived tall fescue plants. Following the vernalization scheme that involved gradual changes of temperature and daylength, seeds were routinely produced from vernalized plants under greenhouse conditions. Molecular analyses of progenies obtained from crosses between transgenic and seed‐derived plants revealed stable meiotic transmission of transgenes following Mendelian inheritance in transgenic tall fescue.     

Physiological Responses of Tomato Plants (Solanum lycopersicum) as Affected by Root Hypoxia

In order to investigate the effects of root hypoxia (1–2 % oxygen) on physiology and on some fructification parameters of tomato plants ( Solanum lycopersicum cv. H63-5), a range of physiological and agronomic measurements were performed on plants submitted to gradual root hypoxia at the second leaf stage. Stomatal conductance (g_s), total chlorophyll content, leaf area (LA) and leaf mass per area (LMA) were quantified at 14 days of treatment in the first leaf appeared before (L1) and after (L3) root hypoxia application. The results obtained showed that 7 days of treatment has slight effects on plant weight growth. However, 14 days of treatment caused decreased root dry weight (DW) with a concomitant increase in shoot DW. Root hypoxia significantly decreased g_s and chlorophyll content of L3, but no effects were noted for L1. LA was significantly reduced for L1 and L3, contrary to LMA which was significantly increased. At the reproductive stage, root hypoxia resulted in a decrease in flower and fruit production, accelerated the entrance in the fruit expansion phase, but did not affect the rate of fruit growth, nor the final fruit size.     

铝胁迫对柑橘实生幼苗生长的影响

每天用含0、0.2、0.6、1.0和1.6 mmol/L AlCl3&#8226;6H2O的1/4 Hoagland营养液浇沙培茶枝柑(Citrus reticulata)、芦柑(C. reticulata)、福橘(C. reticulata)、四川红橘(C. reticulata)、文旦柚(C. grandis)、尤力克柠檬(C. limon)、雪柑(C. sinensis)、酸橙(C. aurantium) (来自湖北)、枸头橙(C. aurantium) (来自浙江)、红木黎檬(C. limonia)、枳壳(Poncirus trifoliata)和枳柚（P. trifoliata × C. grandis）等12个柑橘种类品种实生幼苗3个月。结果表明：雪柑、茶枝柑、芦柑、福橘、四川红橘、尤力克柠檬和枳的耐铝性较强,即使在最高铝（1.6 mmol/L）处理下,其根系、地上部和单株干重均与对照无显著差异;枸头橙、酸橙、红木黎檬和枳柚的耐铝性较差,在最高铝（1.6 mmol/L）处理时,其根系和/或地上部的生长均会受到不同程度的抑制;文旦柚耐铝性最差,最低铝浓度（0.2 mmol/L）处理时,其根系和单株生长量就显著下降。铝胁迫引起茶枝柑、福橘、四川红橘、酸橙和枳实生苗根冠比增加,但对芦柑、枸头橙、尤力克柠檬、红木黎檬、文旦柚和枳柚实生苗根冠比无显著影响;除最低铝处理时雪柑根冠比降低外,其它处理之间无显著差异。     

缺硼对大豆植株生长和根瘤固氮活性的影响

以普通结瘤大豆Ｂｒａｇｇ ｃｖ．（Ｇｌｙｃｉｎｅ ｍａｘ（Ｌ．）Ｍｅｒｒ．）及其超结瘤突变体ｍｔｓ３８２为试验材料,用营养液培养方法研究了缺硼对大豆植株生长和根瘤固氮作用的影响,结果表明,在缺硼条件下,植株根系生长受到抑制,变粗变短,颜色加深;地上部生长点坏死,使植株长得矮小,干重降低;根系结瘤能力和根瘤固氮活性明显下降,说明硼不仅对维持植株的正常生长,同时对根瘤的形成及其固氮活性都起着重要作用。     

Genetic control of photoperiodic sensivity and maturity in spring wheat within narrow limits of adaptation

Summary Photoperiodic respose, as assessed by a regression technique, exhibited complete dominance averaged over the crosses of an eight parent diallel in the vernalized condition. Photoperiodic response as final leaf number for the vernalized 8-hour photoperiod diallel was closely related to photoeriodic response of the regression method. However, the diallel analyses of both sets of data showed little agreement in terms of respectieve array positions.The inheritance of photoperiodic response in diallels using regression values showed little agreement between the vernalized and unvernalized conditions. This difference was postulated to be due to interaction of vernalization and photoperiodic response in the unvernalized situation. In the unvernalized condition photoperiodic response exhibited non-allelic interaction, attributable mainly to the cultivar Pinnacle in general behaviour in its crosses. Its removal gave a situation of high average dominance for photoperiodic response with a clear indication that high photoperiodic sensitivity was dominant to comparative insensitivity.Days to ear emergence (vernalized and 18-hour photoperiod) exhibited non-allelic interaction in its expression, due mainly to the general behaviour of the cultivar Pinnacle in its crosses. Removal of its array gave a situation of a moderately strong degree of overdominance in the expression of days to ear emergence. Maturity differences amongst parents and F₁'s, vernalized and under 18-hour photoperiod, are postulated to be due to a factor other than vernalization or photoperiodic response beheved to be growth temperature in differentially in fluencing growth and/or developmental rates between genotypes.     

品种和外植体对马铃薯脱毒试管苗生长的影响

采用二因素随机区组试验设计,通过测定苗鲜重、根鲜重、苗干重、根干重、叶片数、株高、茎粗、根长、根条数、节长、节数和叶面积等生长指标,研究了品种和外植体对马铃薯脱毒试管苗生物量,地上部和地下部的影响。研究结果表明:3个不同成熟期品种、3种不同外植体部位对马铃薯单株根鲜重、苗干重、根干重、株高、茎粗、节长和根冠比影响有显著性交互作用(p<0.05),说明不同品种和外植体对马铃薯脱毒试管苗生长发育有直接影响,其余性状受品种和外植体交互作用影响不显著;3个不同成熟期品种马铃薯的苗鲜重、根鲜重、苗干重、根干重、叶片数、茎粗、节长、节数、根冠比和根条数受品种影响显著(p<0.05),其余性状受品种影响不显著;3种不同外植体处理对马铃薯的根鲜重、苗干重、根干重、株高、茎粗、节数、叶面积和根冠比有显著性影响(p<0.05),其余性状受3种外植体的影响不显著。其中,以一个节段转接最有利于马铃薯脱毒试管苗的生长。     

Nitrogen Distribution and Dry Matter Accumulation in Oilseed Rape (Brassica napus L.) as Influenced by N Nutrition

A greenhouse experiment was conducted to study N distribution and dry matter accumulation in oilseed rape ( Brassica napus L. cv. Callypso ) in relation to N supply. Three levels of N supply (30, 100 or 170 ppm N) were tested as treatments. Stem and leaf dry weights increased at higher N fertility up to 170 ppm N but root dry weight did not respond to N. Dry matter yield during the vegetative phase was seriously depressed by N deficiency. Most of the plant dry matter was accumulated in the lower segments of the stem and roots. Dry weights of stem and axillary branches increased significantly as N supply increased up to 100 ppm N. Although hull dry weight increased with N supply up to 100 ppm N, seed dry weight did not respond to N. High root N concentration was maintained at 100 or 170 ppm N; but declined as plants advanced in age. N content of leaf and stem also declined with time. Leaf growth was particularly responsive to N fertility and N was mobilised from the older to the younger leaves over time. Nitrogen content of hulls and seeds increased significantly with N supply but N was translocated from the vegetative into the generative organs or from older into younger tissues during pod development. There is need for proper N fertility management in order to achieve successful rape production.     

Root Growth of a Salt Susceptible and a Salt Resistant Rice (Oryza sativa L.) During Seedling Establishment Under NaCl Salinity

The salt susceptible rice ( Oryza sativa L.) cv. Jaya and salt resistant cv. Damodar seed germination and seedling growth rates were studied in laboratory and field conditions. The effect of salinity on seed germination, shoot and root length, seedling vigour index (SVI) and increase in the root: shoot length ratio in the laboratory was relatively more in cv. Jaya than in cv. Damodar. The relative susceptibility to salinity was more in cv. Jaya than in cv. Damodar in the field also. However, their responses varied with growth period. The root: shoot length and fresh and dry weight ratios increased with salinity at 15 days in cv. Jaya. The root: shoot fresh and dry weight ratio decreased with salinity at 15 days in cv. Damodar. However, the root: shoot fresh weight ratio decreased with salinity at 25 days in the susceptible cv. Jaya. The root and shoot length fresh and dry weight of cv. Damodar was enhanced at 0.5% (w/v) NaCl treatment compared to the control seedlings at 25 days. SVI in cv. Jaya decreased with salinity in the laboratory and field conditions. SVI in cv. Damodar, SVI showed little change at 15 days but decreased with salinity of 1–3% NaCl with an enhancement at 0.5% NaCl level in the laboratory and at 25 days in field conditions.     

Developmental responses to vernalization in wheat deletion lines for chromosomes 5A and 5D

The aim of this investigation was to test the developmental patterns of deletion lines, generated for chromosome arms 5AL and 5DL in the variety ‘Chinese Spring’ (CS) under vernalized and non‐vernalized treatments. Plants were grown in controlled conditions under saturating daylength. Time to heading and the duration of particular phases before flowering were recorded, and leaf and spikelet production rates and numbers were analysed. The lines lacking Vrn‐A1 and Vrn‐D1 were delayed in time to heading under non‐vernalized conditions, because of the lengthening of the emergence to floral initiation phase (EM‐FI) and the terminal spikelet to heading phase (TS‐H). Differences in final leaf numbers corresponded to longer durations of the EM‐FI phase. The absence of Vrn‐A1 and Vrn‐D1 apparently decreased the number of spikelets by a lower primordium production rate, even though the duration of the FI‐TS phase was longer or equal to CS. The sensitivity to vernalization in lines where the Vrn genes were deleted was much higher.