Fruit-set after pretreatment with foreign compared with killed compatible pollen

1984 ◽  
Vol 62 (8) ◽  
pp. 1678-1681 ◽  
Author(s):  
W. David Lane

A mechanism based on pollen growth-promoting substances has previously been proposed to explain the effects of mentor (killed compatible) pollen when it improves fertility of crosses between nearly incompatible parents. Similarly, pioneer pollination (two pollinations a day apart) stimulates growth of the last applied pollen and increases fruit-set. In the present experiments the effects of foreign-pollen pioneer treatments on fruit-set of apple, sweet cherry, and apricot were compared with the control, killed compatible pollen. All treatments were followed 24 h later with viable compatible pollen. The foreign pollen, Balsamorrhiza sagittata, did not inhibit fruit-set. When the foreign pollen was heat killed, fruit-set was at least as high as when untreated B. sagittata was used. Two other foreign pollens, Taraxacum officinale and Juniperus communis, resulted in lower fruit-set than B. sagittata but still more than the control. This effect was consistent with a previously hypothesized relationship for mentor pollen, relating size and degree of stimulation. The two nonpollen treatments examined, dried yeast and pectinase solution, slightly inhibited fruit-set. Mineral analysis of a composite of pollen and anther tissue indicated that boron and calcium were not deficient in the control pollen, and incompatibility mechanisms and heat-labile metabolites also were unlikely to have been the cause. No direct evidence was obtained, but pollen growth promotion by a diffusible growth regulator (such as gibberellin) is suggested as plausible and an area worthy of further study.


HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 684d-684
Author(s):  
K.G. Weis ◽  
S.M. Southwick ◽  
Michael E. Rupert

Lack of pollen dispersal was noted in various sites and cultivars of sweet cherry (Prunus avium) following one of California's warmest recorded winters (≈550 hours @ 7°C in the Central Valley). `Bing' cherry is thought to require 850 to 880 hours for adequate budbreak and bloom development. Cross pollination is required by most sweet cherry cultivars for fruit set, including `Bing'. Complete anther dehiscence averaged 13% in `Bing' trees sampled, compared to 52% in `Rainier', 65% in `Brooks', 84.5% in `Burlat', 33% in Van, 23% in `Larian', and 86% in `Black Tartarian'. A range of degree of dehiscence from none to half-open was widely apparent, again by cultivar. Many partially dehiscent anthers did not shed pollen normally but appeared to have the mass of pollen completely adherent inside the pollen sacs. `Black Tartarian', `Larian', and `Burlat' shed pollen readily, however, pollen from dehiscent anthers of other cultivars generally appeared to stick together on the everted locule walls and required direct manipulation to be withdrawn from the pollen sac. Anther morphology ranged from normal size to half normal size, anthers appearing to be without pollen altogether that shriveled on drying, and lobes that were aborted. Pollen germination was low overall: 19% `Bing', 18% `Rainier', 20% `Brooks', 57% `Burlat', 14% `Van', 48% `Larian', and 48% `Black Tartarian'. Poor fruit set in low chill years is often attributed to lack of bloom overlap with pollenizers, however, inadequate chilling also may contribute to low fruit set by inhibiting anther and pollen growth and development. The implications of a critical chilling requirement for normal floral differentiation are that in cherry-growing areas where low chill years are common, pollen may not be viable or transferrable from pollenizers and female gametophytic development also may be impaired.



Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 120
Author(s):  
Guangyu Zhao ◽  
Yihui Wei ◽  
Jiaqi Chen ◽  
Yuhong Dong ◽  
Lingyu Hou ◽  
...  

Purpose: This research was aimed to screen and identify multifunctional phosphorus-dissolving bacteria of a Chinese fir (Cunninghamia lanceolata) plantation and study its phosphorus-dissolving characteristics in order to provide strain resources and a theoretical basis for developing the appropriate bacterial fertilizer of a Chinese fir plantation. Methods: First, phosphorus-dissolving bacteria were isolated from the woodland soil of a Chinese fir plantation by Pikovskava inorganic phosphorus medium (PVK). Then, some growth-promoting indicators of primary screening strains were determined, including the capacity of phosphorus-solubilized, nitrogenase activity, 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity, production of indole-3-acetic acid (IAA), secretion of iron carrier and so on. Finally, the screening multifunctional phosphorus-dissolving bacteria were identified, which were combined with colony characteristics, physiological and biochemical tests and molecular biotechnology. Results: (1) Thirteen phosphorus-dissolving bacteria were isolated and screened in total, and P5 (195.61 mg·L−1) had the strongest capacity of phosphorus-solubilized. Five phosphorus-dissolving bacteria were provided with nitrogenase activity, and the highest activity of nitrogenase was P10 and P5 (71.90 C2H4 nmol·mL−1·h−1 and 71.00 C2H4 nmol·mL−1·h−1, respectively). Four strains were provided with ACC deaminase activity, and the highest activity of ACC deaminase was P5 and P9, (0.74 μmol·mg−1·h−1 and 0.54 μmol·mg−1·h−1, respectively). Most strains could secrete IAA, and three strains of bacteria had a strong secretory ability, which could secrete IAA with a concentration greater than 15 mg·mL−1, and P5 was 18.00, P2 was 17.30, P6 was 15.59 (mg·mL−1). P5 produced carriers of iron better than others, and the ratio of the diameter of the iron production carrier ring to the diameter of the colony was 1.80, respectively, which was significantly higher than other strains. Combining all kinds of factors, P5 multifunctional phosphorus-dissolving bacteria were screened for eventual further study. (2) Strain P5 was identified as Burkholderia ubonensis, based on the colony characteristics, physiological and biochemical tests, 16SrDNA sequence analysis and phylogenetic tree construction. Conclusion: P5 has a variety of high-efficiency growth-promoting capabilities, and the ability to produce IAA, ACC deaminase activity and siderophore performance are significantly higher than other strains, which had great potential in the development of microbial fertilizer.



2015 ◽  
Vol 3 (3) ◽  
pp. 552-560 ◽  
Author(s):  
Mohamed A.M. El-Awady ◽  
Mohamed M. Hassan ◽  
Yassin M. Al-Sodany

This study was designed to isolate and characterize endophytic and rhizospheric bacteria associated with the halophyte plant Sesuvium verrucosum, grown under extreme salinity soil in Jeddah, Saudi Arabia. The plant growth promotion activities of isolated bacterial were evaluated in vitro. A total of 19 salt tolerant endophytic and rhizospheric bacterial isolates were obtained and grouped into six according to genetic similarity based on RAPD data. These six isolates were identified by amplification and partial sequences of 16S rDNA as Enterobacter cancerogenus,Vibrio cholerae, Bacillus subtilis, Escherichia coli and two Enterobacter sp. Isolates were then grown until exponential growth phase to evaluate the atmospheric nitrogen fixation, phosphate solubilization, and production of phytohormones such as indole-3-acetic acid, as well as 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity. While, All of the six strains were negative for ACC deaminaseactivity, two isolates showed Nitrogen fixation activity, three isolates produce the plant hormone (Indole acetic acid) and two isolates have the activity of solubiliztion of organic phosphate. Among the six isolates, the isolate (R3) from the soil around the roots is able to perform the three previous growth promoting possibilities together and it is ideal for use in promoting the growth of plants under the high salinity conditions. This isolate is candidate to prepare a friendly biofertelizer that can be used for the improvement of the crops performance under salinity conditions.Int J Appl Sci Biotechnol, Vol 3(3): 552-560



2021 ◽  
Vol 11 (5) ◽  
pp. 2233
Author(s):  
Maria J. Ferreira ◽  
Angela Cunha ◽  
Sandro Figueiredo ◽  
Pedro Faustino ◽  
Carla Patinha ◽  
...  

Root−associated microbial communities play important roles in the process of adaptation of plant hosts to environment stressors, and in this perspective, the microbiome of halophytes represents a valuable model for understanding the contribution of microorganisms to plant tolerance to salt. Although considered as the most promising halophyte candidate to crop cultivation, Salicornia ramosissima is one of the least-studied species in terms of microbiome composition and the effect of sediment properties on the diversity of plant-growth promoting bacteria associated with the roots. In this work, we aimed at isolating and characterizing halotolerant bacteria associated with the rhizosphere and root tissues of S. ramosissima, envisaging their application in saline agriculture. Endophytic and rhizosphere bacteria were isolated from wild and crop cultivated plants, growing in different estuarine conditions. Isolates were identified based on 16S rRNA sequences and screened for plant-growth promotion traits. The subsets of isolates from different sampling sites were very different in terms of composition but consistent in terms of the plant-growth promoting traits represented. Bacillus was the most represented genus and expressed the wider range of extracellular enzymatic activities. Halotolerant strains of Salinicola, Pseudomonas, Oceanobacillus, Halomonas, Providencia, Bacillus, Psychrobacter and Brevibacterium also exhibited several plant-growth promotion traits (e.g., 3-indole acetic acid (IAA), 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase, siderophores, phosphate solubilization). Considering the taxonomic diversity and the plant-growth promotion potential of the isolates, the collection represents a valuable resource that can be used to optimize the crop cultivation of Salicornia under different environmental conditions and for the attenuation of salt stress in non-halophytes, considering the global threat of arable soil salinization.



Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 888
Author(s):  
Giorgia Novello ◽  
Patrizia Cesaro ◽  
Elisa Bona ◽  
Nadia Massa ◽  
Fabio Gosetti ◽  
...  

The reduction of chemical inputs due to fertilizer and pesticide applications is a target shared both by farmers and consumers in order to minimize the side effects for human and environmental health. Among the possible strategies, the use of biostimulants has become increasingly important as demonstrated by the fast growth of their global market and by the increased rate of registration of new products. In this work, we assessed the effects of five bacterial strains (Pseudomonas fluorescens Pf4, P. putida S1Pf1, P. protegens Pf7, P. migulae 8R6, and Pseudomonas sp. 5Vm1K), which were chosen according to their previously reported plant growth promotion traits and their positive effects on fruit/seed nutrient contents, on a local onion cultivar and on zucchini. The possible variations induced by the inoculation with the bacterial strains on the onion nutritional components were also evaluated. Inoculation resulted in significant growth stimulation and improvement of the mineral concentration of the onion bulb, induced particularly by 5Vm1K and S1Pf1, and in different effects on the flowering of the zucchini plants according to the bacterial strain. The present study provides new information regarding the activity of the five plant growth-promoting bacteria (PGPB) strains on onion and zucchini, two plant species rarely considered by the scientific literature despite their economic relevance.



2021 ◽  
Vol 16 (8) ◽  
pp. 75-80
Author(s):  
Pitchaiah Pelapudi ◽  
Sasikala Ch ◽  
Swarnabala Ganti

In the present rapid growing world, need for a sustainable agricultural practice which helps in meeting the adequate food demand is much needed. In this context, plant growth promoting bacteria were brought into the spot light by the researchers. Though the plant growth promoting bacteria have several beneficial applications, due to some of the disadvantages in the field conditions, they lagged behind. In the current research work, native PGPR were isolated from the rhizosphere soil samples of maize with an aim to isolate the nitrogen fixing, phosphate solubilising and potash solubilising bacteria. Out of the several isolates, potent PGPR isolates viz., Paenibacillus durus PCPB067, Bacillus megaterium PCBMG041 and Paenibacillus glucanolyticus PCPG051 were isolated and identified by using the 16 S rRNA gene sequencing studies. Genomic DNA sequences obtained were deposited in the NCBI Genbank and accession numbers were assigned as MW793452, MW793456 and MW843633. In order to check the efficacy of the PGPR isolates, pot trials were conducted by taking maize as the host plant. Several parameters viz. shoot length, shoot weight, root length, root weight and weight of the seeds were tested in which PGP treatment showed good results (shoot length - 187±3.5 cm, shoot weight - 31±4 g, root length - 32±3.6 cm, root weight - 17±2 g, yield- 103.3±6.1 g) when compared to the chemical fertilizer treatment (shoot length - 177±3.5 cm, shoot weight - 25±3.6 g, root length - 24±3.5 cm, root weight - 14.6±1.52 g, yield- 85.6±7.6 g). Based on the results, it can be stated that these native PGPR isolates can be effectively used in the plant growth promotion of maize.



2017 ◽  
Vol 5 (5) ◽  
Author(s):  
Vanessa Nessner Kavamura ◽  
Suikinai Nobre Santos ◽  
Rodrigo Gouvêa Taketani ◽  
Rafael Leandro Figueiredo Vasconcellos ◽  
Itamar Soares Melo

ABSTRACT The strain of Bacillus sp. CMAA 1363 was isolated from the Brazilian Caatinga biome and showed plant growth-promoting traits and ability to promote maize growth under drought stress. Sequencing revealed genes involved in stress response and plant growth promotion. These genomic features might aid in the protection of plants against the negative effects imposed by drought.



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