Trait collection of rice by cold tolerance

Author(s):  
Z.Z. Petkevich

Goal. To assess rice cultivars for cold tolerance; to select the most valuable in terms of economic characteristics sources for their further use in breeding; to create a trait collection on their basis.Result and Discussion. The article presents the results of studying a rice collection. The collection material is represented by 51 accessions of different eco-geographical origin (European, Eastern, Mid-Asian, Latin American). The accessions belong to two subspecies: japonica and indica. Most of the accessions (22) are from Ukraine and account for 43.1%. Temperature is one of the most important environmental factors affecting the crop establishment and development. In Ukraine, rice is cultivated in the most northern zone of rice growing and, therefore, it is liable to negative effects of cold weather during the seed germination, sprouting, anthesis and grain ripening. Consequently, it is essential for breeders to create cultivars that will be tolerant to low temperatures during the sprouting period, with high field germinability and increased germinative power. Seed germination is particularly affected by temperature. Fifty one rice cultivars were investigated for the seedling development, seed germination rate and seedling growth intensity at 14°C; possible states of embryonic roots were estimated; lengths of these stages were determined. Selection of material with a set of parameters allowed forming a trait collection with increased levels of resistance to abiotic environmental factors. In breeding, it is very important to identify sources of valuable traits and to assess extent of their influence on the plant performance. The research distinguished rice accessions for breeding by levels of cold tolerance, performance and its components. We selected six donors of several valuable traits, the use of which will enhance the breeding efficiency (Kuban 3, Vikont, UkrNDS 8839, Ontario, VNIIR 546, Kaz ER – 6). Thus, the comprehensive assessment of the accessions allowed us not only to replenish the rice gene pool, but also, basing on this research, to choose starting material to involve it in further breeding for creating new cold-tolerant varieties. While creating such cultivars, we revealed morphological traits of rice, which are used as test parameters characterizing the stress tolerance of accessions.Conclusions. The study resulted in formation of the trait collection representing the genetic diversity of cultivars and breeding lines. Each trait and gradation has corresponding standards. Cultivars-standards reflect more specific and stable expression of a trait. The collection was created by 4 basic traits and 3 gradations and contains accessions from 9 countries (Ukraine, Russia, Kazakhstan, Uzbekistan, Kyrgyzstan, USA, Bulgaria, China, and Hungary). The standard accessions selected can serve as sources of economically valuable features to create starting material for breeding.

Agronomy ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 190
Author(s):  
Lei Chu ◽  
Yiping Gao ◽  
Lingling Chen ◽  
Patrick E. McCullough ◽  
David Jespersen ◽  
...  

White clover (Trifolium repens L.) is cultivated as a forage crop and planted in various landscapes for soil conservation. There are numerous reports of failed white clover stands each year. A good understanding of the seed germination biology of white clover in relation to environmental factors is essential to achieve successful stand establishment. A series of experiments were conducted to investigate the impacts of light, temperature, planting depth, drought, and salt stress on seed germination and the emergence of white clover. White clover is negatively photoblastic, and seed germination averaged 63 and 66% under light and complete dark conditions 4 weeks after planting (WAP), respectively. Temperature affected the seed germination speed and rate. At 1 WAP, seeds incubated at 15 to 25 °C demonstrated a significantly higher germination rate than the low temperatures at 5 and 10 °C; however, the germination rate did not differ among the temperature treatments at 4 WAP. The results suggest that white clover germination decreases with increasing sowing depths, and the seeds should be sown on the soil surface or shallowly buried at a depth ≤1 cm to achieve an optimal emergence. White clover seeds exhibited high sensitivity to drought and salinity stress. The osmotic potential and NaCl concentration required to inhibit 50% seed germination were −0.19 MPa and 62.4 mM, respectively. Overall, these findings provide quantifiable explanations for inconsistent establishment observed in field conditions. The results obtained in this research can be used to develop effective planting strategies and support the successful establishment of white clover stands.


Genome ◽  
2016 ◽  
Vol 59 (2) ◽  
pp. 137-145 ◽  
Author(s):  
Hari D. Upadhyaya ◽  
Yi-Hong Wang ◽  
Dintyala V.S.S.R. Sastry ◽  
Sangam L. Dwivedi ◽  
P.V. Vara Prasad ◽  
...  

Sorghum is one of the world’s most important food, feed, and fiber crops as well as a potential feedstock for lignocellulosic bioenergy. Early-season planting extends sorghum’s growing season and increases yield in temperate regions. However, sorghum’s sensitivity to low soil temperatures adversely impacts seed germination. In this study, we evaluated the 242 accessions of the ICRISAT sorghum mini core collection for seed germination and seedling vigor at 12 °C as a measure of cold tolerance. Genome-wide association analysis was performed with approximately 162 177 single nucleotide polymorphism markers. Only one marker locus (Locus 7-2) was significantly associated with low-temperature germination and none with vigor. The linkage of Locus 7-2 to low-temperature germination was supported by four lines of evidence: strong association in three independent experiments, co-localization with previously mapped cold tolerance quantitative trait loci (QTL) in sorghum, a candidate gene that increases cold tolerance and germination rate when its wheat homolog is overexpressed in tobacco, and its syntenic region in rice co-localized with two cold tolerance QTL in rice. This locus may be useful in developing tools for molecular breeding of sorghums with improved low-temperature germinability.


2020 ◽  
Vol 8 ◽  
Author(s):  
Xiao-Hui Zhou ◽  
Wei-Ming He

Plant performance is commonly temperature-dependent so that this performance could vary with climate warming. Seeds are among the most important propagules of plants, and seed traits strongly influence plant invasion success. Therefore, understanding seed traits under climate warming is useful for predicting invasion risks. To this end, we conducted a warming experiment with an infrared radiator and examined the effects of 5 years warming (approximately 2°C above ambient) on the seed quality and subsequent germination of Solidago canadensis from North America, where it is native (24 native populations), and from China, where it is invasive (29 invasive populations). Temperature regimes (i.e., ambient vs. warming) interacted with population sources (i.e., native vs. invasive) to significantly influence seed germination, but not thousand-seed mass. Warming significantly advanced the seed germination timing of native S. canadensis populations and increased their seed germination rate; warming did not influence the germination timing but decreased the germination rate of invasive S. canadensis populations. Across two temperature regimes combined, 24 native S. canadensis populations had smaller seeds, later germination timing, and lower germination rate than 29 invasive S. canadensis populations. These findings suggest that climate warming could facilitate the seed germination of native but not invasive populations. Our data also highlight that invasive populations might be more successful than native populations due to better seed quality and faster and higher seed germination.


HortScience ◽  
2006 ◽  
Vol 41 (5) ◽  
pp. 1330-1331 ◽  
Author(s):  
J.S. Shin ◽  
P. Raymer ◽  
W. Kim

Seashore paspalum (Paspalum vaginatum O. Swartz) is a perennial warm-season grass that is rapidly gaining popularity for use on golf courses and athletic fields. The first seeded cultivar of seashore paspalum was recently developed. Seed from the pilot production of this cultivar harvested in Oregon during 2002 by Turf-Seeds, Inc. demonstrated a high level of apparent seed dormancy with a tetrazolium test of 91% but a germination rate of less than 5% at room temperature. This seed was used in laboratory experiments to determine the effect of a number of environmental factors on germination response in this new turf species. Treatment factors are germination media, constant and alternating (night/day) temperatures, and light. A strong and significant effect of temperature on germination was observed. Total germination was increased at higher temperatures. At the same daytime temperature, seed germination under alternating temperature was better than germination at constant temperature. The effect of light on germination was significant at 20, 25, 30, 20/35 °C in water and at 25/35 °C in 0.2% KNO3 germination media. However, the effect of light on germination in KNO3 media was not significant at 35 °C constant and 20/30 °C alternating temperatures. Alternating temperature used in conjunction with KNO3 media reduced the requirement for light. The use of 0.2% KNO3 rather than water as the germination media increased germination in most temperature and light treatments. Based on our results, maximum germination percentage was obtained when seed was germinated at 35 °C constant or 20/35 °C alternating temperature. However, when we consider field application, 25/35 °C with light is more realistic condition in field. Therefore, recommended seed germination test condition is at 25/35 °C with KNO3 treatment.


2020 ◽  
Author(s):  
Lei Chu ◽  
Yiping Gao ◽  
Lingling Chen ◽  
Patrick E. McCullough ◽  
David Jespersen ◽  
...  

AbstractWhite clover (Trifolium repens L.) is cultivated as a forage crop and planted in various landscapes for soil conservation. There are numerous reports of failed white clover stands each year. A good understanding of seed germination biology of white clover in relation to environmental factors is essential to achieve successful stand establishment. A series of experiments were conducted to investigate the impacts of light, temperature, planting depth, drought, and salt stress on seed germination and emergence of white clover. White clover is negatively photoblastic, and seed germination averaged 63 and 66% under light and complete dark conditions at 4 weeks after planting (WAP), respectively. Temperature affected seed germination speed and rate. At 1 WAP, seeds incubated at 15 to 25 °C demonstrated significantly higher germination rate than the low temperatures at 5 and 10 °C; however, the germination rate did not differ among the temperature treatments at 4 WAP. Results suggest that white clover germination decreases with increasing sowing depths and the seeds should be sown on the soil surface or shallowly buried at a depth ≤1 cm to achieve an optimal emergence. White clover seeds exhibited high sensitivity to drought and salinity stress. The osmotic potential and NaCl concentration required to inhibit 50% seed germination was −0.19 MPa and 62.4 mM, respectively. Overall, these findings provide quantifiable explanations for inconsistent establishment observed in field conditions. The findings obtained in this research can be used to develop effective planting strategies and support the successful establishment of white clover stands.


Weed Science ◽  
2012 ◽  
Vol 60 (4) ◽  
pp. 558-563 ◽  
Author(s):  
Neha Rana ◽  
Barton J. Wilder ◽  
Brent A. Sellers ◽  
Jason A. Ferrell ◽  
Gregory E. MacDonald

Smutgrass is an invasive warm-season perennial bunch-type grass native to tropical Asia. The two varieties of smutgrass prevalent in Florida are small smutgrass and giant smutgrass. Laboratory seed germination experiments were conducted on both smutgrass varieties to determine the effect of various environmental factors on germination and emergence. The average germination rate for both varieties was 88% at 30/20 C day/night temperatures. Seed germination for both varieties was greater under simulated temperature flux than at constant temperatures. Seed of both varieties germinated at four simulated Florida temperature fluxes (22/11, 27/15, 33/24, and 29/19 C day/night), although the germination of small smutgrass and giant smutgrass was reduced at 33/24 and 22/11 C, respectively. Germination of small and giant smutgrass under dark conditions was 27 and 53%, respectively. Both smutgrass varieties germinated over a wide range of pH values. Small and giant smutgrass germination was inhibited at water potentials below −0.2 MPa and when small smutgrass seed was placed below the soil surface. Emergence of giant smutgrass seed did not occur below 3 cm. Both smutgrass varieties germinated over a broad range of environmental conditions, indicating their capability of year-round germination; however, germination is only likely to occur under field conditions during the summer growing season when rainfall is prevalent. These results indicate that both species have the ability to germinate over a wide range of environmental conditions but that germination is inhibited by moisture stress and depth of burial. Considering that giant smutgrass prefers higher temperatures than small smutgrass, the advent of rainfall from June through September is conducive for germination. Practices that focus on the germination pattern of smutgrass could lead to better long-term management of smutgrass in Florida.


2019 ◽  
Vol 20 (15) ◽  
pp. 3796 ◽  
Author(s):  
Xin Wang ◽  
Chao Yu ◽  
Yi Liu ◽  
Lu Yang ◽  
Yang Li ◽  
...  

Low temperature is an environmental stress factor that is always been applied in research on improving crop growth, productivity, and quality of crops. Polyunsaturated fatty acids (PUFAs) play an important role in cold tolerance, so its genetic manipulation of the PUFA contents in crops has led to the modification of cold sensitivity. In this study, we over-expressed an ω-3 fatty acid desaturase from Glycine max (GmFAD3A) drove by a maize ubiquitin promoter in rice. Compared to the wild type (ZH11), ectopic expression of GmFAD3A increased the contents of lipids and total PUFAs. Seed germination rates in GmFAD3A transgenic rice were enhanced under low temperature (15 °C). Moreover, cold tolerance and survival ratio were significantly improved in GmFAD3A transgenic seedlings. Malondialdehyde (MDA) content in GmFAD3A transgenic rice was lower than that in WT under cold stress, while proline content obviously increased. Meanwhile, the activities of superoxide dismutase (SOD), hydroperoxidase (CAT), and peroxidase (POD) increased substantially in GmFAD3A transgenic rice after 4 h of cold treatment. Taken together, our results suggest that GmFAD3A can enhances cold tolerance and the seed germination rate at a low temperature in rice through the accumulation of proline content, the synergistic increase of the antioxidant enzymes activity, which finally ameliorated the oxidative damage.


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