Germination Response of Rice Seeds to Constant and Alternating Temperatures

Abstract For physiologically dormant (PD) species in fire-prone environments, dormancy can be both complex due to the interaction between fire and seasonal cues, and extremely deep due to long intervals between recruitment events. Due to this complexity, there are knowledge gaps particularly surrounding the dormancy depth and cues of long-lived perennial PD species. This can be problematic for both in situ and ex situ species management. We used germination experiments that tested seasonal temperature, smoke, dark and heat for 18 PD shrub species distributed across temperate fire-prone Australia and assessed how germination was correlated with environmental factors associated with their home environments. We found extremely high levels of dormancy, with only eight species germinating above 10% and three species producing no germination at all. Seven of these eight species had quite specific seasonal temperature requirements and/or very strong responses to smoke cues. The maximum germination for each species was positively correlated with the mean temperature of the source population but negatively correlated with rainfall seasonality and driest months. The strong dependence on a smoke cue for some of the study species, along with examples from other studies, provides evidence that an obligate smoke response could be a fire-adapted germination cue. Germination response correlated with rainfall season of the source populations is a pattern which has often been assumed but little comparative data across sites with different rainfall seasonality exists. Further investigation of a broader range of species from different rainfall season environments would help to elucidate this knowledge gap.

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Application of vigor indexes to evaluate the cold tolerance in rice seeds germination conditioned in plant extract

Scientific Reports ◽

10.1038/s41598-021-90487-x ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Sheila Bigolin Teixeira ◽

Stefânia Nunes Pires ◽

Gabriele Espinel Ávila ◽

Bruna Evelyn Paschoal Silva ◽

Victoria Novo Schmitz ◽

...

Keyword(s):

Low Temperatures ◽

Seed Priming ◽

Dry Mass ◽

Economic Losses ◽

Tolerance Index ◽

Promising Tool ◽

Germination Speed ◽

Cold Tolerant ◽

Rice Seeds ◽

Carrot Extract

AbstractRice is a crop that presents sensitivity to cold, especially in the germination phase, which leads to high economic losses. Alternative management forms are essential to increase tolerance to low temperatures, and seed priming represents a promising tool. The objective of this study was to investigate the priming effect of the aqueous extract of carrot roots on rice seeds to increase tolerance to low temperatures during germination. Seeds from cultivars BRS Querência (cold-susceptible) and Brilhante (cold-tolerant) were soaked for 24 h in concentrations of 0, 25, 50, and 100% carrot extract, sown on germitest paper and conditioned in BOD for 21 days at 15 °C. As a control, the seeds soaked in water were also germinated at 25 °C. They were evaluated for germination, first germination count, and germination speed index to calculate the stress indices: tolerance index, susceptibility index, and harmonic mean. They were also evaluated for the length and dry mass of shoot and root. The results showed that the rice seeds conditioning in carrot extract effectively reduces the damage caused by cold, significantly increasing the germination speed and the percentage of final germination and the growth evaluations, more expressive at 100% concentration. The stress indexes are efficient in estimating the tolerance of the cultivars and the effect of the different conditions in low-temperature conditions, highlighting the superiority of the Brilhante cultivar.

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Pathogenic association of Albifimbria terrestris with rice seeds

Indian Phytopathology ◽

10.1007/s42360-021-00355-x ◽

2021 ◽

Author(s):

Anju Bala Sharma ◽

Atul Kumar ◽

Shaily Javeria

Keyword(s):

Rice Seeds

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Variation of seed germination response to temperature in tomato landraces: An adaptation strategy to environmental conditions

Scientia Horticulturae ◽

10.1016/j.scienta.2021.109987 ◽

2021 ◽

Vol 281 ◽

pp. 109987

Author(s):

Naeimeh Sousaraei ◽

Benjamin Torabi ◽

Kambiz Mashaiekhi ◽

Elias Soltani ◽

Seyyed Javad Mousavizadeh

Keyword(s):

Seed Germination ◽

Environmental Conditions ◽

Adaptation Strategy ◽

Germination Response ◽

Response To Temperature

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Label-free non-invasive classification of rice seeds using optical coherence tomography assisted with deep neural network

Optics & Laser Technology ◽

10.1016/j.optlastec.2020.106861 ◽

2021 ◽

Vol 137 ◽

pp. 106861

Author(s):

Deepa Joshi ◽

Ankit Butola ◽

Sheetal Raosaheb Kanade ◽

Dilip K. Prasad ◽

S.V. Amitha Mithra ◽

...

Keyword(s):

Neural Network ◽

Optical Coherence Tomography ◽

Deep Neural Network ◽

Optical Coherence ◽

Label Free ◽

Non Invasive ◽

Rice Seeds

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Evaluating the effect of aging process on the physicochemical Characteristics of rice seeds by low field nuclear magnetic resonance and its imaging technique

Journal of Cereal Science ◽

10.1016/j.jcs.2021.103190 ◽

2021 ◽

pp. 103190

Author(s):

Ping Song ◽

Zhaoyi Wang ◽

Peng Song ◽

Xia Yue ◽

Yuhe Bai ◽

...

Keyword(s):

Nuclear Magnetic Resonance ◽

Magnetic Resonance ◽

Aging Process ◽

Imaging Technique ◽

Physicochemical Characteristics ◽

Low Field ◽

Rice Seeds ◽

Nuclear Magnetic

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LAMP-based foldable microdevice platform for the rapid detection of Magnaporthe oryzae and Sarocladium oryzae in rice seed

Scientific Reports ◽

10.1038/s41598-020-80644-z ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

M. K. Prasannakumar ◽

P. Buela Parivallal ◽

Devanna Pramesh ◽

H. B. Mahesh ◽

Edwin Raj

Keyword(s):

Magnaporthe Oryzae ◽

Plant Pathogens ◽

Point Of Care ◽

Lamp Assay ◽

Rice Seed ◽

Highly Sensitive ◽

Polymerase Chain ◽

Rice Seeds ◽

Template Dna ◽

Assay Conditions

AbstractRice blast (caused by Magnaporthe oryzae) and sheath rot diseases (caused by Sarocladium oryzae) are the most predominant seed-borne pathogens of rice. The detection of both pathogens in rice seed is essential to avoid production losses. In the present study, a microdevice platform was designed, which works on the principles of loop-mediated isothermal amplification (LAMP) to detect M. oryzae and S. oryzae in rice seeds. Initially, a LAMP, polymerase chain reaction (PCR), quantitative PCR (qPCR), and helicase dependent amplification (HDA) assays were developed with primers, specifically targeting M. oryzae and S. oryzae genome. The LAMP assay was highly efficient and could detect the presence of M. oryzae and S. oryzae genome at a concentration down to 100 fg within 20 min at 60 °C. Further, the sensitivity of the LAMP, HDA, PCR, and qPCR assays were compared wherein; the LAMP assay was highly sensitive up to 100 fg of template DNA. Using the optimized LAMP assay conditions, a portable foldable microdevice platform was developed to detect M. oryzae and S. oryzae in rice seeds. The foldable microdevice assay was similar to that of conventional LAMP assay with respect to its sensitivity (up to 100 fg), rapidity (30 min), and specificity. This platform could serve as a prototype for developing on-field diagnostic kits to be used at the point of care centers for the rapid diagnosis of M. oryzae and S. oryzae in rice seeds. This is the first study to report a LAMP-based foldable microdevice platform to detect any plant pathogens.

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