Density Studies on Lupins: I. Flower Development

In an August-sown experiment the pattern of flower developmentwas followed for cv. Ultra (Lupinus albus L.) and cv. Unicrop(L. angustifolius L.) grown at low (10 plants m^–2) andhigh (93 and 83 plants m^–2, Ultra and Unicrop respectively)densities. Dry weight increase of flowers on the main-stem inflorescenceand first lateral below the main-stem were compared at differentfloral stages. Maximum flower weight was reached just priorto the open flower stage and remained constant or declined untila pod formed or abscission occurred. The time period betweenmaximum flower weight and pod formation or abscission was upto 10 days. Emergence of the inflorescence was earlier and thefirst flower of Ultra opened 10 days before Unicrop. Developmentof each terminal raceme (inflorescence) was acropetal, withpods having formed on lower flower nodes when terminal flowerswere still quite immature. Laterals forming the next generationof inflorescences grew from axillary leaf buds below an inflorescencewhile it was in full flower. Sources of competition from connectedreproductive and vegetative metabolic sinks are discussed. Lupinus spp., lupins, flower development, planting density     

A Flower and Pod Staging System for Soybean

Flower and pod abscission limit soybean yield. A system forquantifying flower and pod development based on the morphologicalappearance of the flower prior to and following anthesis hasbeen developed to aid in studies of pod abscission. Changesin the appearance of the corolla, primarily the banner petal,are used to distinguish the different stages of the system.External pistil dimensions have been correlated with internalfeatures for each stage of development. From anthesis to podset, pistil length and weight increase almost two- and fivefold,respectively, and ovule development progresses from unfertilizedegg cells to embryos surrounded by cellular endosperm. Pod determinedare correlated with ovule length and width and embryo cell number.Flower and pod stages can be determined in situ, thus permittingnon-destructive observation and experimental manipulation offlowers or pods without necessarily impeding their development.Stages have been identified that indicate precisely when podset occurs and when young pods cease growing and ultimatelyabscise. This system of flower and pod staging is useful instudies designed to assess effects of abiotic or biotic stressand genetic factors on pod set and abortion. Abscission, anthesis, Glycine max (L.) Merr, embryo development, pod set     

Regeneration of Walking Legs in the Fiddler Crab Uca pugilator

SYNOPSIS. Regeneration of walking legs in the fiddler crab Ucapugilator is most efficient when it follows autotomy (the reflexiveloss of a limb). Closure of the wound and would healing occurimmediately following autotomy and visible regeneration beginswithin a few days. Regeneration of the walking leg occurs intwo distinct stages: The first stage, called Basal Growth, involvesmitosis and differentiation. The second stage involves primarilyprotein synthesis and water uptake and is called ProecdysialGrowth. Proecdysial Growth is, in part, under direct hormonalstimulation.     

CHANGES IN THE CONTENT OF GIBBERELLIN-LIKE SUBSTANCES IN RIPENING SEED AND POD OF LUPINUS LUTEUS

The amount of gibberellin-like substances in seed, pod, embryoand "endosperm" of Lupinus luteus in relation to their developmentwas studied by means of the rice seedling test. The amount of gibberellin-like substances per seed increasedremarkably at the first stage of development, when the growthof seed and pod was very slow, and attained its maximum at suchan early stage as the dry weight of seed reached a value ofonly 10 per cent and that of pod 28 per cent of their respectivemaximum levels. Changes in amount of gibberellin-like substancespresent in the pod were very closely related to the changesin growth of pod. Gibberellin-like substances equivalent to0.3 µg gibberellin A₃ per seed and 0.028 µg perpod were found at the 20th day after anthesis, and no activityin mature seed and 0.09 µg per pod at the 50th day. Noactivity was found in the embryo itself at all stages, indicatingthat the gibberellin-like substances in seed occur only in the"endosperm," i.e. in the tissues that will eventually form testain fully ripened stage. (Received December 18, 1962; )     

Anatomical and Biochemical Changes Associated with the Induction of Oilseed Rape (Brassica napus) Pod Dehiscence by Dasineura brassicae (Winn.)

Dehiscence of pods at an early stage of development is a characteristicof oilseed rape pods damaged by Dasineura brassicae (pod midge).Anatomical examination of pods exhibiting symptoms of infestationrevealed a loss of cohesion between intact cells of the dehiscencezone, a narrow tissue of thin-walled cells present between thevalve margins. Determination of hydrolytic enzyme activity inpericarp tissues of damaged siliquae showed localized enhancementof both polygalacturonase (EC 3.2.1.15 [EC] ) and cellulase (ß1,4 glucanase, EC 3.1.2.4 [EC] ) activity, positionally consistent withthese factors being responsible for the observed cell wall degradation.Mechanistic similarities of midge-induced and maturation-associatedpod dehiscence are discussed. Oilseed rape, Brassica napus L. cv., Bienvenu, pod shatter, pod midge, Dasineura brassicae (Winn.), cellulase, polygalacturonase     

Endoreduplication Occurs during Pod Wall Development in Temperate Grain Legumes

Differentiation to a specialized function in plant tissue isassociated with an increase in the DNA content of the cellsover the diploid state. Using flow cytometry, ploidy levelswere assessed during pod development in three white lupin genotypesunder three environmental conditions and in other lupin speciesand temperate grain legumes in one environmental condition.Endoreduplication was found in the pod walls of all genotypesstudied. Higher ploidy levels coincided with maximal growthof the pod. DNA replication was not related to the proportionof the pod that comprised walls. Endoreduplication also occurredin other temperate grain legumes with at least two DNA duplicationsduring the development of the pod walls. The biological significanceof endoreduplication in the pod walls of grain legumes is unknown,but could be related to the storage function of these organs.Copyright2000 Annals of Botany Company Lupinus species, Pisum sativum, Phaseolus vulgaris, Vicia faba, pod wall development, ploidy level, flux cytometry, Bis-benzimide Hoechst 33258     

Photomorphogenesis of the Gynophore, Pod and Embryo in Peanut, Arachis hypogaea L.

Darkened excized gynophores ceased to elongate after 8–10days in vitro and started to form a pod. Gynophore elongationwas inhibited to a greater extent in total darkness than underlow irradiance, while pod and embryo growth was stimulated indarkness only. Intact gynophores, enclosed in transparent vials containingglass beads, continued to elongate in both light and darkness.In light the elongating gynophores thickened as they penetratedbetween the glass beads, forming a seedless pod at the bottomof the vials. In the dark the elongating gynophores producedsmall pods in which the seeds had started to grow. Excized gynophores elongated in vitro under continuous whitelight at a rate similar to that of intact exposed gynophores.The rate of elongation in vitro, was lower under continuousblue or red-enriched light, than under white light, and wasfurther reduced under continuous far-red irradiation. Pods didnot form during any of the continuous irradiation treatmentsbut only after transfer to darkness, the largest pods formingafter continuous far-red irradiation. As little as 10 min daily exposure to red or far-red irradiancehad the same effect on gynophore elongation as continuous irradiation.Pods formed only when the daily periods of far-red irradiationwere 30 min or less. Reducing the daily exposures to 2 min decreasedthe time to onset of pod formation from 30 to 16 days. Far-redfollowing red irradiation was effective in inhibiting gynophoreelongation stimulated by red irradiation. Pod formation in red/far-redirradiation was only 50 per cent of that observed in far-redirradiation. The involvement of light in continual gynophoreelongation and in the concomitant inhibition of proembryo growthis discussed. Arachis hypogaea L., peanut, gynophore, photomorphogenesis, embryo development, pod development, proembryo     

Development of Oilseed Rape Buds, Flowers, and Pods In Vitro

A technique for growing buds, flowers, and pods of oilseed rape(Brassica napus L. cv. Haplona) on stem explants in vitro hasbeen developed. Open flowers and young pods underwent normaldevelopment on a basal medium of minerals, vitamins, and sucrosebut the development of buds was less successful. Young buds(3 mm long) did not develop and only limited development ofthe older buds (5 mm long) took place. Some 3 mm-long buds wereinduced to develop to open flowers by adding naphthyl aceticacid or gibberellic acid. Pod and seed set in open flowers werenot affected by adding plant growth substances to the medium,but pod elongation and pod dry weight were promoted by gibberellicacid, 105 M, and benzyl amino purine, 10⁷ M, respectively. Reducingthe supply of sucrose or minerals to open flowers reduced seedset, pod elongation and pod weight but did not affect pod set.The physiological significance of the results is discussed. Key words: In vitro cultures, oilseed rape, pod development, flower development     

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     

Effect of Removal of Flower Buds, Open Flowers, Young Pods and Shoot Apex on Growth and Pod Set in Soybean

The complete removal of the reproductive structures once andshoot apices of soybeans (Glycine max L. Merrill) during earlyanthesis but before the rapid seed development stage significantlyincreased flowering and pod set in greenhouse and field grownplants. The treated plants had darker green leaves, shorterstems and petioles and retained their chlorophyll content longerthan control plants. Pod maturation was also delayed. Althoughdecapitation and the removal of reproductive structures increasedthe number of 3- or more-seeded pods in all varieties tested,seed weight per plant was not consistently increased. The possibleinvolvement of endogenous hormones in pod set and multi-loculepod production in soybeans is discussed. Key words: Glycine max (L.) Merr, Reproductive structures, Shoot apex, Growth, Flowering, Pod set, Multi-locule pods     

Temporal and nutritional factors modulate responses to abscisic acid and osmoticum in their regulation of storage protein synthesis in developing seeds of alfalfa (Medicago sativa L.)

Storage protein synthesis during alfalfa (Medicago sativa L.)seed development displays a temporal pattern and is regulatedboth by ABA and low osmotic potentials. Deposition of the 2S,7S and 11S storage proteins occurs maximally at the mid–to late stages of development. Osmoticum, but not ABA alonecould effectively induce storage protein synthesis at earlystages of development in isolated alfalfa embryos placed onwater for several days. Neither ABA nor osmoticum alone couldmaintain storage protein synthesis in isolated late-stage embryosplaced on water. On the other hand, isolated developing embryoscultured on a nutrient (Murashige and Skoog) medium could maintainstorage protein synthesis in the presence of ABA and osmoticum,alone or in combination, for up to 14 d after being dissectedfrom the pod. Of the components of this medium, the inorganicsalts appeared to be the most important. The response to ABAand osmoticum varied with the time of isolation during developmentwith the greatest enhancement of storage protein synthesis inisolated embryos coinciding with the time of maximum synthesiswithin the seed when in planta. Addition of ABA and osmoticumafter the time of maximum storage protein synthesis did notelevate the amount of synthesis, but rather prolonged the timeover which it could take place. Thus, while the amplitude ofstorage protein synthesis could be modified by ABA or osmoticum,the inherent temporal pattern, with maximum synthesis occurringonly at mid– to late stages of embryo development, couldnot. Key words: Embryogenesis, Medicago sativa L., alfalfa, abscisic acid, osmotic potential, storage protein synthesis, nutrient supply     

Larval development of Brachynotus gemmellari (Rizza, 1839) (Brachyura, Grapsidae) reared under laboratory conditions

The complete larval development of the grapsid crab Brachynorusgemmellari (Rizza, 1839) was obtained by culture in the Iabomtoiy.Five zoeal stages, the megalopa and the first crab stage aredescribed and illustrated. Larval development from hatchingto first crab took 26 days at 20C. The morphological charaeiarsof the larvae of B.gemmellari are compared with those of otherknown larvae of the genus Brachynosus.     

Changes in Carbohydrate, Amino Acid and Phenol Contents in Cocoa Pods from Three Clones after Infection with Phytophthora megakarya Bra. and Grif.

Mature pods from three clones ofTheobroma cacaoL., differingin their susceptibility toPhytophthora megakaryaBra. and Grif.,were infected with the fungal mycelium. Variations of the contentsin carbohydrates, ketohexoses, amino acids, phenols and flavonol,and hydroxycinnamic derivatives were followed in the cortexfor 4d. After pod infection, the amount of carbohydrates decreasedmore rapidly in the clone SNK10 (highly susceptible) than inthe clones SNK413 (low susceptibility) and ICS95 (mildly susceptible),suggesting their utilization by the fungus. At the same time,the amount of ketohexoses decreased by 22% in the clone SNK10,remained almost constant in the clone SNK413, and increasedby 53% in the clone ICS95. The content of amino acids increasedwith time in the pods of the three clones. The results suggestthat the amino acid variation is related to pod aging and tothe infection. Four days after treatment, an increase in phenolicswas measured in all cases. The increase in flavonol and hydroxycinnamicderivatives was related to the wounding and to the infectionof the pods. DuringPhytophthorablack pod development, variationsof the contents in the biochemicals studied herein were genotype-dependent,and the patterns of the changes could be related, at least inpart, to the susceptibility of the genotype toP. megakarya. Theobroma cacaoL.; cocoa; black pod; plant/fungus interaction; susceptibility     

Defoliation and its Effects on Pod and Seed Development in Oil Seed Rape (Brassica napus L.)

Both in vivo and in vitro techniques have been used to followthe development of individual pods on the terminal inflorescenceof undefoliated and defoliated plants of oil-seed rape (Brassicanapus cv. Maris Haplona). For any pod, a rapid increase in podlength occurred between 2 d and 8 d after flower opening andthis preceded by approximately 2 d the increase in pod width,the rate of which was less than that for length. An increasein the diameter of individual seeds coincided with the increasein pod width. Regional increases in the length and width ofpods were associated with the presence of developing seeds inthese regions. Key words: Brassica napus L., Development, In vivo, Pod and seed, Stress     

Gastrulation in Calcareous Sponges: In Search of Haeckel's Gastraea

Haeckel's studies of development in calcareous sponges (1872)led him to develop the "Gastraea Theory," which proposes thatthe ancestral mode of germ layer formation, or gastrulation,was by invagination to produce a functional gut. His observationsthat gastrulation in the Calcarea occurs by invagination ofa ciliated larva upon settlement and metamorphosis were supportedby remarkable photomicrographs of the stage by Hammer in 1908.Although no later work found the same stage, these conceptsare repeated in texts today. We have re-examined embryogenesisand metamorphosis in Sycon sp. cf. S. raphanus in order to understandwhen gastrulation occurs. Almost all larvae settle on theirciliated anterior pole and metamorphose into a bilayered juvenilewhose interior cells rapidly differentiate into choanocytesand other cells of the young sponge. After a four-year searchwe have found the transitory stage shown by Hammer in whichthe anterior cells invaginate into the posterior half of thelarva. The hole closes and it is not until some days later thatthe sponge forms an osculum at its apical pole. To understandwhether invagination comprises gastrulation and if the holecan be considered to be a blastopore we have carried out a reviewof the literature dealing with this brief moment in calcaroneansponge development. Despite the intrigue of this type of metamorphosis,we conclude that gastrulation occurs earlier, during formationof the two cellular regions of the larva, and that metamorphosisinvolves the reorganization of these already differentiatedregions. Considering the pivotal position occupied by the Calcareaas the possible sister-group to all other Metazoa, these resultscall for a reassessment of germ layer formation and of the relationshipsof the primary germ layers among basal metazoan phyla.     

Biochemical Changes in Nodules of Vigna mungo (L.) During Vegetative and Reproductive Stages of Plant Growth in the Field

Nitrogenase activity in root nodules of Vigna mungo L. attaineda peak at the flowering stage and declined thereafter. Levelsof soluble proteins, particularly leghaemoglobin, and ratesof protein and RNA synthesis declined with nitrogenase. Activitiesof protease and RNase increased with the ageing or nodules.Carbohydrate utilization, sugar levels and ATP were maximumat the early pod stage and gradually declined with age. Theseinterrelated changes point to a loss of nitrogenase activityas the first indicator of nodule senescence that is linked withflowering. Later, losses of proteins, total sugar and ATP wererelated to increased RNase and protease activity and decreasedhexokinase and to a loss in capacity to incorporate amino acidinto protein.Copyright 1993, 1999 Academic Press Vigna mungo (L.), senescene, nitrogenase, leghaemoglobin, field experiments     

Laboratory studies on the larval growth and development of Nyctiphanes capensis (Euphausiacea)

Larvae of Nyctiphanes capensis Hansen were reared in the laboratoryunder different trophic conditions (i.e., algal, animal andmixed diets) from the second calyptopis stage to the first juvenilestage. It is demonstrated that diet is important in determininggrowth rates and development of the larvae. The highest growthrates were achieved on diets of Artemia nauplii mixed with eitherthe flagellate Tetraselmis or Pseudodiaptomus nauplii. Poorerdietary conditions such as with the diatom Phaeodactylum yieldedslower growth rates where additional moults were needed to completefurcilia development. Under favourable trophic conditions theintermoult period was 4–6 days and was not age dependent.Three dominant pathways of pleopod development were found inhealthy individuals.     

The Influence of Genes ar and n on Senescence in Pisum sativum L.

The effect of genes ar (violet flowers, small hilum) and n (thick,fleshy pod wall) on whole plant in senescence peas was examinedby comparing Ar- with arar and N- with nn plants in segregatingprogenies. Homozygosity for ar or n significantly delayed the time whenthe plants were ready for harvest of their entire seed crop.These genes did not delay either the onset of reproduction orthe onset of apical arrest in the first instance. However, whereasAr- N- plants almost invariably senesced and died as the firstseed crop matured, the majority of arar and/or nn plants entereda period of secondary growth and a further fruiting cycle. Comparedwith Ar- plants, arar plants had over twice as many pods andseeds but individual seeds were 58 per cent lighter and totalseed yield (wt) was 19 per cent less. Pod length was unaffected.Compared with N-plants, nn plants had shorter pods (16 per cent),fewer seeds per pod (21 per cent), smaller seeds (20 per cent)and a lower total seed yield (wt 14 per cent less). It appearsthat ar and n impose a lower metabolic drain per reproductivenode as a consequence of their effects on hilum anatomy andpod morphology, respectively. These mutants disrupt the normalpattern of monocarpic senescence by breaking the coordinationbetween apical arrest and subsequent events. The developingseed crop delimited by the first arrest fails to cause plantdeath, possibly because sink size is less than in normal counterparts. Pisum sativum L, garden pea, senescence, hilum, pod, seed size, genetics     

Specificity of Gibberellin and Sucrose-promoted Flower Bud Growth in Gladiolus

A critical stage in flower bud growth in the spike of Gladioluswhich is initiated by gibberellic acid (GA₃) and sustained bysucrose has been identified. This corresponds to the stage atwhich separation of the outer bract occurs. In buds at differentdevelopmental stages isolated and held in water, it is the samebud stage that first shows increased growth. Buds not inducedby light were shown to respond more significantly to GA₃ andsucrose than those induced by light. Since the separation ofthe outer bract results in light-induced amylase productionand starch hydrolysis leading to petal growth, it is proposedthat growth promotion by GA₃ is related to light-induced petalgrowth at this specific stage. flower bud growth, Gladiolus natalensis, gibberellic acid, sucrose     

The effect of salinity and temperature on the larval development of Mithrax caribbaeus Rathbun, 1920 (Brachyura: Majidae) reared in the laboratory

Larvae of Mithrax caribbaeus were reared in the laboratoryin a factorial experiment employing three temperatures (22,25 and 28°C) and three salinities (32, 35 and 38). Survivaland duration of larval stages were recorded. Ovigerous femalesof M.caribbaeus were collected from the south-eastern coastof Margarita Island, Venezuela, and maintained in individualaquaria until hatching. Eggs from three of the females hatchedin the laboratory. Larvae from each hatching were subdividedinto groups of 10 and reared in plastic bowls containing 200ml filtered and UV-irradiated sea water at different temperature–salinitycombinations. Larvae were transferred daily to clean bowls withnewly hatched Artemia nauplii, and the number of molts and mortalitywithin each bowl was recorded. Complete larval development ofM.caribbaeus occurred under all experimental conditions. Salinityhad the greatest effect on percentage survival of each larvalstage and complete development up to the first crab stage. Thefirst zoeal stage exhibited the highest survival rate. Maximumsurvival for this stage occurred at 25°C, 32–35. Survivalin the second zoeal stage and the megalopa was affected onlyby salinity. Effects of temperature and salinity on survivaldecreased with advance in development. The duration of the twozoeal stages, the megalopa, and development to the first crabstage showed a gradual reduction with increasing temperature.Salinity showed an effect on the duration of zoeal stages butnot on the megalopal stage. Development from hatching to thefirst crab stage required 8–18 days, depending on thetemperature–salinity combination, and was inversely relatedto temperature, averaging 14.3 days at 22°C, 11.8 days at25°C and 9.2 days at 28°C.