Field Bean Plants Research Articles

Interactions between and within inflorescences in relation to the storage capacity of field beans (Vicia faba)

SummaryTwo field experiments and one pot experiment were carried out to test the hypothesis that competition and dominance relations between and within inflorescences control seed yield. The experiments compared untreated field bean (Vicia faba L.) plants with others in which the numbers of inflorescences and flowers had been surgically reduced to 18 defined positions at lower or at upper nodes. Growth conditions were varied by sowing date and plant density. Seed yields, yield components and 14C-labelled assimilate distribution were determined.Most untreated plants set no more than 18 pods while treated ones set 4–7 pods fewer. As variation in seed set per pod was small, the resulting number of seeds remained about 30% less in treated compared with untreated plants. In plants with pods set only at upper nodes, 14C-assimilate distribution shifted in favour of leaf and root production, presumably supporting seed production later on. Concerning seed yield per plant, full compensation was reached as mean weights per seed increased up to 40%. In interactions with growth conditions, small overcompensation effects on seed yield per plant were indicated. Results are discussed in relation to storage capacity and yield stability.

Organic Acids as Sources for Drought-induced Proline Synthesis in Field Bean Plants, Vicia faba L.

Summary The involvement of organic acids in proline synthesis was studied using different parts from 6-week-old field bean plants after treatment for one day of withholding water and/or light. Water stress induced proline accumulation; N came from nitrate and the C skeleton from organic acids. Loss of nitrate and carboxylates was compensated by synthesis of organic acids of oxidative respiration (citrate, malate, and lactate) to maintain electroneutrality. The concentrations of proline as well as the concentrations of organic acids in parts of water-stressed plants were multiples of corresponding concentrations in plant parts under normal conditions of water supply and light exposure. A functional relation existed between multiples of proline and corresponding multiples of organic acids of the oxidative respiration; the correlation coefficient was 0.8. Increases in concentration of proline and of the above-mentioned acids were due to water loss and increased synthesis; all other drought-induced increases in organic-acid concentrations were a consequence of water loss only. Withholding of light did not prevent proline synthesis in water-stressed plants; ammonia assimilation, which is closely linked to photorespiratory acids (glycerate and glycollate), could not be involved in proline synthesis. It is reasoned that organic acids of oxidative respiration are the direct sources of proline accumulation in plants under conditions of a water deficit. This proline synthesis occurs via glutamate dehydrogenase and is an efficient metabolic mechanism to remove an excess of H + ions.

Dry matter accumulation at specific pod positions on field bean (Vicia faba L.) plants and possible relations with indoleacetic acid and abscisic acid levels

Seed weights at specific positions within inflorescences of field bean plants (Vicia faba L.) were varied by removal of flowers. The inflorescences of two regions (nodes 3+4 and nodes 5+6, counted from the bottom of the plant) were used for manipulations and investigations. The two proximal flowers of the manipulated inflorescence were removed in order to vary the development and seed weights of distal pods (see Fig. 1). Dry matter accumulation and IAA- and ABA-concentrations in seeds were investigated during the filling period. Treatment effects in both regions were similar during two seasons. The removal of proximal flowers prevented the usually observed drop of distal pods and favoured the accumulation of dry matter and IAA in seeds, whereas the variation of ABA-concentrations partly depended on interaction with season. Whether these effects contribute to a signal leading to the establishment of processes preceeding dry matter accumulation or are a consequence of such processes is questionable.

The sources of free proline and asparagine in field bean plants, Vicia faba L., during and after a short period of water withholding

Interconversions between free and bound amino acids were studied in the organs of 8-weeks-old field bean plants during two days of water withholding and one day after re-supply of water. At the end of the period of water stress, the increase in proline concentration in the vegetative parts was 10- to 25-fold but in the generative parts not more than 3-fold. The largest amount of proline was found in the lower part of the stem and in the roots; most protein was broken down in the young leaves. During the first day of water deficit, the existing pool of free and bound amino acids served as sources of accumulated proline and asparagine. The amounts of proline and asparagine which accumulated during the second day, came for 15% from the amino-transfering components (total of glutamine, glutamate, aspartate, alanine, serine and glycine), derived from protein. Of the total amount 85 % was newly synthesized from sources other than the amino acid pool. After re-supply of water, protein synthesis resumed. Asparagine proceeded to accumulate and the amount of proline decreased slightly. It is concluded that the system of amino-transfering components is directly involved in the reactions of the plant to water stress.

Indirect effects of air pollutants: Changes in plant/parasite interactions

The impact of air pollutants on plant/parasite-interactions has been investigated. It could be demonstrated that fumigation of Vicia faba L. with 0·15 ppm SO 2 (400 μg m −3) or 0·2 ppm NO 2 (400 μg m −3) during 7 days caused changes in plant metabolism which resulted in higher growth rates of the aphid Aphis fabae Scop. feeding on these plants. Fumigation of V. faba with 0·085 ppm O 3 during 2 or 3 days, however, caused decreased aphid growth on fumigated plants. That result could be reversed by higher O 3 concentrations or through the presence of NO x during O 3 fumigation. Ambient air comprising a mixture of pollutant gases had a strong enhancing effect on aphid performance. Thus, the growth of A. fabae on field bean plants was significantly higher in ambient summertime. London air than in charcoal-filtered air. Similarly, the growth of Macrosiphon rosae L. on rose bushes ( Rosa sp., cv. Nina Weibull) was improved in ambient summertime Munich air; the increase in growth rate averaged about 20%.

Transmission characteristics and some other properties of bean yellow vein‐banding virus, and its association with pea enation

SUMMARYBean yellow vein‐banding virus (BYVBV) has been found occasionally in mixed infection with pea enation mosaic virus (PEMV) in spring‐sown field beans (Vicia faba minor) in southern England. Glasshouse tests confirmed that, like PEMV, BYVBV is transmissible by manual inoculation and by aphids in the persistent manner. However, BYVBV can be transmitted by aphids only from plants that are also infected with a helper virus, usually PEMV. Thus after separation from PEMV by passage through Phaseolus vulgaris it was no longer aphid‐transmissible. It became aphid‐transmissible again only after re‐mixing in plants with PEMV or with a substitute helper, bean leaf roll virus (BLRV). It was not transmitted by aphids that fed sequentially on plants singly infected with PEMV and BYVBV. Thus the interaction between BYVBV and PEMV (or BLRV) that enables BYVBV to be transmitted by aphids seems to occur only in doubly infected plants. However, it was not transmitted by aphids from plants doubly infected with BYVBV and broad bean wilt virus (BBWV). BYVBV and PEMV were transmitted more readily by Acyrthosiphon pisum than by Myzus persicae; neither virus was transmitted by Aphis fabae.Phenol extracts of BYVBV‐infected leaves were more infective than phosphate buffer or bentonite‐clarified extracts and were sometimes infective when diluted to 1/1000. The infectivity of BYVBV in phosphate buffer extracts of leaves singly infected with BYVBV, unlike that in extracts of leaves doubly infected with BYVBV and PEMV (or BLRV), was destroyed by treatment with organic solvents. BYVBV infected 11 of 28 plant species that were inoculated with phenol extracts; seven of the infected species were legumes. No transmission of BYVBV was detected through seed harvested from infected field bean plants. Isometric particles c. 30 nm in diameter were seen in extracts of plants doubly infected with BYVBV and PEMV but not in extracts of plants infected with BYVBV alone. Leaves of plants infected with BYVBV, alone or with PEMV, contained membrane‐bound structures c. 50–90 nm in diameter associated with the tonoplast in cell vacuoles. These structures were not found in healthy leaves.BYVBV has several properties in common with other known aphid‐borne viruses that are helper‐dependent and transmitted in a persistent manner. Possibly, as suggested for some of them, aphid transmission of BYVBV depends on the coating of its nucleic acid with helper virus coat protein.

The Distribution of Free Amino Acids, Especially of Proline, in the Organs of Field Bean Plants, Vicia faba L., during Development in the Field

Concentrations of free and bound proline and total free amino acidswere measured in the organs of field bean (cv. Minica), grown under field conditions. The very young seeds of 95-day-old plants had a very high content of more than 1mg free proline per gram fresh weight. The free proline content of leaves and pod walls did not exceed 0.1 mg per g fresh weight. The ratios of free proline and total free amino acid concentrations in the different organs were not constant during the development of the plants. The ratio of the free and bound proline concentrations was very high by the time the youngest seeds and pod walls were sampled and decreased rapidly during the further process of ripening to a value which was comparable to the ratios of the other organs. This very high ratio was not a consequence of a water shortage. It is therefore suggested that free proline has a characteristic function in the development of the generative organs.

Necrosis in field beans (Vicia faba) induced by interactions between bean leaf roll, pea early‐browning and pea enation mosaic viruses

SUMMARYMixed infections with two or three viruses ‐ bean leaf roll (BLRV), pea early‐browning (PEBV) and pea enation mosaic (PEMV) ‐ were detected in plants showing leaf curling, stunting and necrosis in a crop of field beans grown for seed in 1980. In glasshouse tests, field bean plants infected with any one of these viruses showed no necrosis, and plants infected with PEBV and PEMV together showed symptoms of PEMV only. However, mixed infection with BLRV and PEMV almost invariably induced severe stunting and leaf necrosis, and infection with BLRV and PEBV often induced both leaf and stem necrosis and sometimes caused early death. Thus it seems that the necrotic symptoms seen in the field were induced by interactions between BLRV and the other viruses.No transmission of PEBV was detected through seed harvested from the crop, but up to 5% transmission was detected through seed from experimentally‐infected plants. The infected seedlings were symptomless.

Robbing of Field Bean Flowers by the Short-Tongued Bumble BeeBombus TerrestrisL.

SummaryMost flowers produced during early flowering of autumn-sown field beans had small holes in the base of the corolla which indicated that they had been robbed by Bombus terrestris. The proportion of robbed flowers decreased as flowering continued. Slightly fewer flowers of spring-sown plants were robbed. There was no evidence of damage to the reproductive structures of 100 robbed flowers of the cultivar Maris Bead. Of the flowers sampled from the third, fourth and fifth flowering nodes of field bean plants growing near shelter at the paddock margin, 62% were robbed. Of the pods which subsequently formed at these nodes 59% were from flowers which had been robbed. This suggests that robbing of the flower by short-tongued bumble bees did not prejudice either pollination by other insects or pod development.

Identification of multiple forms of glutamine synthetase in field bean ( Vicia faba L.)

Glutamine synthetase (GS) activity was detected after electrophoresis on starch gels using the glutamyl transfer reaction. Two bands of GS activity (designated GS 1 and GS 2) were observed in a chloroplast fraction and four bands (designated GS 1, GS 2, GS 4 and GS 5) in a total leaf extract from field beans. GS 4 and GS 5 were assumed to be cytoplasmic GS. Differences in the chloroplast GS bands (GS 1 and GS 2) but not in the cytoplasmic bands (GS 4 and GS 5) were observed between cultivars and between lines of the same cultivar. No differences in GS banding patterns were noted between extracts from pods or subtended leaves sampled at different stages of development. Other field bean plants were grown from seed in perlite moistened with distilled water and then pretreated with solutions of NaNO 3, NH 4NO 3, NH 4Cl or urea for either 1 or 7 days. Electrophoresis of root extracts from plants pretreated for 1 day with NH 4NO 3, NH 4Cl or urea revealed the presence of 1 band of GS activity, designated GS 3, clearly distinguished from the 2 forms in the leaf cytoplasm. An additional band with a mobility similar to one of those in the chloroplast, GS 1, was found in root extracts of plants given NaNO 3 or NH 4NO 3 for 1 week, but not in those pretreated with NH 4Cl or urea. Incubation of the starch gel with methionine sulphoximine (MSO) in the presence of ATP and Mg 2+ prior to the detection of GS activity prevented any bands being observed. The possible roles of these different forms of GS are discussed in the light of previously reported evidence.

Wirksamkeit der symbiontischen N2-Fixierung der Körnerleguminosen in Abhängigkeit von Rhizobienimpfung, Substrat, N-Düngung und 14C-saccharoselieferung

Cultivation experiments (Mitscherlich-vessels, quartz sand, 15N-labelled soil, 15N-fertilizer) showed, that various strains of Rhizobium lupini (white and yellow lupines) and of Rhizobium leguminosarum (field beans and peas) induced a different N2-fixation of the inoculated plants, the most effective Rhizobium strains being 367a, Cz, T3, 271 (Rh. lupini), and Azotogen (Rh, leguminosarum). Yellow lupines and field bean plants were supplied with N2 from the air considerably better than white lupines and peas after inoculation with the most effective Rhizobium strains. Application of mineral N to the white lupines and peas not only substituted the inhibited N2-fixation, but increased N amounts in the plants. White lupines fixed more N2 under soil conditions than in quartz sand. An experiment with steam-sterilized and 15-labelled soil as a comparative substrate showed, that this finding was mainly caused by an additional Rhizobium infection from the soil. Contrary to field beans and yellow lupines which fix N2 up to ripeness, white lupines and peas finished N2-fixation in the time of flowering. Mineral-N applied at that time was an additional source of N for last-named plants and they utilized it for production of higher protein yields. Continual spraying of white lupine plants with 14C-labelled sucrose solution after the time of flowering caused continuance of N2-fixation up to the stage of ripeness. It is assumed that the cause of this effect was the competition of growing seeds and nodules for the photosynthates. The supply of nodules was inadequate without external sucrose application. Mineral N inhibited the sucrose-induced N2-fixation of white lupine nodules and their consumption of photosynthates. Consequently, the applied 14C was transported into seeds to a larger extent. The investigations allow the following conclusion: Effective N2-fixation requires nodules being a powerful sink for assimilates on the basis of a highly efficient photosynthetic system of the host plant.

Parthenocarpy and Internal Competition in Vicia fabaL.

Summary By preventing pollination of decapitated field bean plants parthenocarpic pods were produced consistently. No exogenous growth substances were applied. Evidence accumulated using such an approach helped explain causes of flower failure in this crop. A further consequence of this work is that it has become possible to study the physiology of the developing pod independently of that of seeds.

Incidence, field spread, seed transmission and effects of broad bean stain virus and Echtes Ackerbohnenmosaik‐Virus in Vicia faba in eastern Scotland

SUMMARYIn eastern Scotland seed‐borne infection with broad bean stain virus (BBSV) and/or Echtes Ackerbohnenmosaik‐Virus (EAMV) was detected in five of 39 seed lots of field bean in 1975 and in four of 21 commercial crops of field bean or broad bean sampled in 1975 or 1976. Tests failed to detect the main weevil vector of these viruses, Apion vorax, in 1975 and 1976 but Sitona weevils were found in most crops and were numerous in many, reaching maximum numbers in August. No spread of BBSV and EAMV was detected in commercial crops containing seed‐borne infection. In experimental field bean crops containing plants manually inoculated with virus, no virus spread was detected in 1975, and only 0–015% uninoculated plants became infected with EAMV in 1976. Sitona, therefore, was an inefficient vector.The percentage of virus infection in seed harvested from field bean plants manually inoculated 3, 5, 7 and 11 wk after emergence in the field was 1–5, 2–7, 0–4 and 0–06 for BBSV and 0–5, 2‐1, 0–6 and 0 for EAMV respectively. Seed harvested from unrogued and rogued plots of field bean grown from seed containing 3–4% seed‐borne infection produced 0–05% and no infected plants, respectively. Yield losses in field bean plants manually inoculated with virus before flowering were up to 20% but were much greater in plants infected through the seed. Loss in yield was largely caused by a decrease in number of seeds per pod.The absence of A. vorax, the late arrival of Sitona weevils in the crop and their inefficiency as vectors, and the smaller effects of BBSV and EAMV on crop yield than in southern England appear to make eastern Scotland very suitable for the production of bean seed free from BBSV and EAMV.

Absorption and Re‐distribution of Nitrogen during Growth and Development of Field Bean, Vicia faba

AbstractThe absorption of nitrate by field bean plants at different times of development was investigated to determine the distribution and subsequent utilization of N up to the maturity of the beans.Nodulated plants were grown in sand culture and pulse‐labelled with 15NO3 for 4 short periods during development. Whole plants were sampled at intervals until maturity and analysed for total nitrogen and 15N.There was a rapid increase in the bean dry weight and total N after fruit set and, at maturity, the beans contained about three times as much N as had ever been in the rest of the plant. Nitrate absorption continued steadily throughout plant development but nodule N fixation made a progressively greater contribution to the total N in the plant. Over a quarter of the total 15N absorbed was found in the roots immediately after each treatment and little of this was subsequently translocated upwards in spite of the large increase in shoot N taking place. Above ground the most powerful “sink” for recently absorbed and redistributed N was initially the youngest vegetative tissue. However after fruit set competition developed between the growing tip and the developing beans until at the later stages the beans became the more powerful. Quantitatively redistribution made only a small contribution to bean N.

Growth and Cadmium Accumulation of Plants Grown on a Soil Treated with a Cadmium‐Enriched Sewage Sludge

AbstractCorn, wheat, rice, field bean, soybean, cabbage, spinach, lettuce, curlycress, carrot, turnip, radish, tomato, and squash plants were grown to commercial harvest stage using as the substrate, soil pre‐treated with a municipal sewage sludge (1%) containing variable amounts of CdSO4 up to 640 µg Cd/g soil. Observations included injury symptoms, yield decrement, Cd level of diagnostic tissue, and Cd and Zn content of harvested produce. Cadmium‐sensitive plants such as spinach, soybean, curlycress, and lettuce were injured by soil Cd levels of 4–13 µg Cd/g soil; whereas, tomato and cabbage tolerated soil levels of approximately 170 µg Cd/g soil without exhibiting injury symptoms. Rice was tolerant at all levels tested. Leafy plants such as lettuce, spinach, and turnip greens (tops) accumulated 175 to 354 µg Cd/g; whereas, fruit and seed tissue of plants under comparable treatment, with the exception of soybean, accumulated no more than 10 to 15 µg Cd/g tissue. The concentrations for soybean extended up to 30 µg Cd/g tissue. Paddy rice exhibited no ill effects for soil Cd treatments up to 640 µg Cd/g soil. Grain of plants under the 640 µg Cd/g treatment contained 2 µg Cd/g tissue. DPTA‐extractable Cd correlated (r=0.99) with the level of CdSO4 added to the substrate.

Intra‐specific mechanisms in relation to the natural regulation of numbers of Aphis fabae Scop

SUMMARYParthenogenetic virginoparous apterae of Aphis fabae Scop. on field beans (Vicia faba) reproduced faster initially in populations of eight colonizing apterae than in those with 2–4 or 16–32 per plant. The aphids were at first mutually benefited but were quickly affected by competition as numbers rose above the critical density represented by about eight apterae and their first progeny. This is because the aphids remained densely aggregated and seemingly created a local shortage despite abundant food and space elsewhere on the plant. Such self‐induced competition provides the basis for self‐regulation of numbers of A. fabae in relation to (1) food and space provided by the growing plant and (2) mortality from natural enemies and from other causes including insecticides.As competition increased, the multiplication of A. fabae populations slowed, newly formed adult apterae emigrated and increasing numbers of alatae were formed. The mean weights of apterae decreased from about 1·8 mg. to 0·3 mg. and of alatae from 0·9 to 0·2 mg. Such decrease probably favours production of many adults that might otherwise fail to mature.Experiments in a glasshouse and in field cages indicated the success with which an A. fabae population adapts to and exploits a growing plant. Field bean plants sown in mid‐March and infested as in the field produced an average of 15,000–17,000 A. fabae emigrants per plant of which 78–84% were adults (mostly alatae). This is equivalent to about 1600 million alate emigrants from 1 acre (0·4 hectare) of an infested field bean crop.

The pollination requirements of broad beans and field beans (Vicia faba)

1. Broad bean plants caged with bees produced more seeds per pod, more seeds per plant, heavier seeds and a greater weight of seeds per plant than plants caged without bees. They also had more mature pods at the first harvest but the total number of pods picked was about the same for cages with and without bees. The flowering season of plants caged without bees was extended.2. Field bean plants caged with bees had more seeds per pod and more seeds per plant than plants without bees.3. For both crops, plants in the open had about double the number of pods, beans and weight of beans as plants in cages.

THE POLLINATION REQUIREMENT OF THE FIELD BEAN (VICIA FABA)

Many of the flowers on field bean plants fail to produce pods even when fully pollinated. When insect pollination is prevented pod production on the lowest inflorescences, which normally produce most pods, is reduced but a compensatory increase on the upper ones ensures a moderate yield. This change in the distribution of pods may be a useful indication of insufficient pollination.

Self- and cross-fertility in field beans (Vicia faba Linn.)

1. Controlled self- and cross-pollinations were performed on field bean plants. It was found that while manipulation of the flower stimulated seed setting, both self- and cross-pollination were equally effective.2. Estimations of pollen germination on artificial medium, to which had been added extracts of styles or ovaries from the same or a different plant, gave some slight evidence of a specific inhibition by ‘self’ extracts. No analogous effect was detected on pollen tube growth.3. Experiments in which the style was cut at varying intervals after pollination detected no difference between self- and foreign pollen in rate of growth through the style. Pollen placed on stigmas of immature flowers began growth at once although the fertility achieved was less than when mature flowers were used.4. The composition of seed from mixed self- and cross-pollination was examined. Early application of foreign pollen increased the proportion of crossfertilization but the results were similar in hybrids and inbreds.5. Flower manipulation was more effective in stimulating seed setting than shaking the plants. Spraying with hormone solution was ineffective.6. It was found that plants varied in their capacity to set seed without flower manipulation (autofertility). Hybrid plants were more autofertile than plants from inbred lines.7. X-ray pictures of unopened flowers suggested that the pollen may be more abundant and less diffuse in hybrids than in inbreds.8. The expression of autofertility was affected by many genetic factors.9. Seed produced by open pollination of F1 hybrids contained a much higher proportion derived from self-pollination than did seed from inbred plants grown in the same plot. Possible explanations for this difference, and some consequences for the population genetics of the species, are discussed.