Drought tolerance, phosphorus efficiency and yield characters of upland rice<br>lines

Abstract Main conclusions Sugar-mediated osmotic acclimation and a strong antioxidative response reduce drought-induced biomass loss at the vegetative stage in rice. Abstract A clear understanding of the physiological and biochemical adaptations to water limitation in upland and aerobic rice can help to identify the mechanisms underlying their tolerance to low water availability. In this study, three indica rice varieties-IR64 (lowland), Apo (aerobic), and UPL Ri-7 (upland)-, that are characterized by contrasting levels of drought tolerance, were exposed to drought at the vegetative stage. Drought-induced changes in biomass, leaf metabolites and oxidative stress markers/enzyme activities were analyzed in each variety at multiple time points. The two drought-tolerant varieties, Apo and UPL Ri-7 displayed a reduced water use in contrast to the susceptible variety IR64 that displayed high water consumption and consequent strong leaf dehydration upon drought treatment. A sugar-mediated osmotic acclimation in UPL Ri-7 and a strong antioxidative response in Apo were both effective in limiting the drought-induced biomass loss in these two varieties, while biomass loss was high in IR64, also after recovery. A qualitative comparison of these results with the ones of a similar experiment conducted in the field at the reproductive stage showed that only Apo, which also in this stage showed the highest antioxidant power, was able to maintain a stable grain yield under stress. Our results show that different metabolic and antioxidant adaptations confer drought tolerance to aerobic and upland rice varieties in the vegetative stage. The effectiveness of these adaptations differs between developmental stages. Unraveling the genetic control of these mechanisms might be exploited in breeding for new rice varieties adapted to water-limited environments.

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Improvement of Upland Rice Variety by Pyramiding Drought Tolerance QTL with Two Major Blast Resistance Genes for Sustainable Rice Production

Rice Science ◽

10.1016/j.rsci.2021.07.009 ◽

2021 ◽

Vol 28 (5) ◽

pp. 493-500

Author(s):

Vishalakshi Balija ◽

Umakanth Bangale ◽

Senguttuvel Ponnuvel ◽

Kalyani Makarand Barbadikar ◽

Srinivas Prasad Madamshetty ◽

...

Keyword(s):

Drought Tolerance ◽

Resistance Genes ◽

Upland Rice ◽

Blast Resistance ◽

Rice Variety ◽

Rice Production ◽

Blast Resistance Genes

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Carbon Isotope Discrimination in Soluble Carbohydrates and Drought Tolerance in Upland Rice

Photosynthesis: Mechanisms and Effects ◽

10.1007/978-94-011-3953-3_603 ◽

1998 ◽

pp. 2569-2572

Author(s):

A. Scartazza ◽

M. Lauteni ◽

M. C. Monteverdi ◽

A. Augusti ◽

L. Spaccino ◽

...

Keyword(s):

Drought Tolerance ◽

Carbon Isotope ◽

Carbon Isotope Discrimination ◽

Upland Rice ◽

Soluble Carbohydrates ◽

Isotope Discrimination

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High-yielding NERICA mutant rice for upland areas and hope for Bangladeshi farmers.

10.1079/9781789249095.0006 ◽

2021 ◽

pp. 53-64

Author(s):

Mirza Mofazzal Islam ◽

Shamsun Nahar Begum ◽

Rigyan Gupta

Keyword(s):

Drought Tolerance ◽

Grain Yield ◽

Crop Production ◽

Upland Rice ◽

Vital Role ◽

High Yield ◽

Rice Varieties ◽

Commercial Cultivation ◽

Drought Tolerant ◽

Different Doses

Abstract Drought is an important stress phenomenon in Bangladesh that greatly hampers crop production. So, it is imperative to develop drought-tolerant rice varieties. Low-yielding, non-uniform flowering and late-maturing Africa rice - New Rice for Africa (NERICA), viz. NERICA-1, NERICA-4 and NERICA-10 varieties - were irradiated with different doses of gamma-rays (250, 300 and 350 Gy) in 2010. M1 plants were grown and M2 plants were selected based on earliness and higher grain yield. The desired mutants along with other mutants were grown as the M3 generation during 2011. A total of 37 mutants from NERICA-1, NERICA-4 and NERICA-10 were selected on the basis of plant height, short duration, drought tolerance and high yield in the M4 generation. In the M5 generation, six mutants were selected for drought tolerance, earliness, grain quality and higher yield. With respect to days to maturity and grain yield (t/ha), the mutant N1/250/P-2-6-1 of NERICA-1 matured earlier (108 days) and had higher grain yield (5.1 t/ha) than the parent. The mutant N4/350/P-4(5) of NERICA-4 also showed a higher grain yield (6.2 t/ha) than its parent and other mutants. On the other hand, NERICA-10 mutant N10/350/P-5-4 matured earlier and had a higher yield (4.5 t/ha) than its parent. Finally, based on agronomic performance and drought tolerance, the two mutants N4/350/P-4(5) and N10/350/P-5-4 were selected and were evaluated in drought-prone and upland areas during 2016 and 2017. These two mutants performed well with higher grain yield than the released upland rice varieties. They will be released soon for commercial cultivation and are anticipated to play a vital role in food security in Bangladesh.

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Characteristics of the root system in two Brazilian upland rice varieties which exhibit contrasting behavior towards drought tolerance

Semina Ciências Agrárias ◽

10.5433/1679-0359.2020v41n2p421 ◽

2020 ◽

Vol 41 (2) ◽

pp. 421-434

Author(s):

Leandro Martins Ferreira ◽

◽

Cristiana Maia de Oliveira ◽

Leilson Novaes Arruda ◽

Renan Pinto Braga ◽

...

Keyword(s):

Drought Tolerance ◽

Root System ◽

Upland Rice ◽

Rice Varieties

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Microbial Diversity of Upland Rice Roots and Their Influence on Rice Growth and Drought Tolerance

Microorganisms ◽

10.3390/microorganisms8091329 ◽

2020 ◽

Vol 8 (9) ◽

pp. 1329

Author(s):

Zhiqiang Pang ◽

Ying Zhao ◽

Peng Xu ◽

Diqiu Yu

Keyword(s):

Drought Stress ◽

Drought Tolerance ◽

Plant Growth ◽

Upland Rice ◽

Oryza Sativa L ◽

Soluble Sugar ◽

Stress Conditions ◽

Rice Roots ◽

Microbial Resources

Among abiotic stresses, drought is one of the most important factors limiting plant growth. To increase their drought tolerance and survival, most plants interact directly with a variety of microbes. Upland rice (Oryza sativa L.) is a rice ecotype that differs from irrigated ecotype rice; it is adapted to both drought-stress and aerobic conditions. However, its root microbial resources have not been explored. We isolated bacteria and fungi from roots of upland rice in Xishuangbanna, China. Four hundred sixty-two endophytic and rhizospheric isolates (337 bacteria and 125 fungi) were distributed. They were distributed among 43 genera on the basis of 16S rRNA and internal transcribed spacer (ITS) gene sequence analysis. Notably, these root microbes differed from irrigated rice root microbes in irrigated environments; for example, members of the Firmicutes phylum were enriched (by 28.54%) in the roots of the upland plants. The plant growth-promoting (PGP) potential of 217 isolates was investigated in vitro. The PGP ability of 17 endophytic and 10 rhizospheric isolates from upland rice roots was evaluated under well-irrigated and drought-stress conditions, and 9 fungal strains increased rice seedling shoot length, shoot and root fresh weight (FW), antioxidant capability, and proline (Pro) and soluble sugar contents. Our work suggests that fungi from upland rice roots can increase plant growth under irrigated and drought-stress conditions and can serve as effective microbial resources for sustainable agricultural production in arid regions.

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