scholarly journals Introgression of drought tolerance QTLs through marker assisted backcross breeding in wheat (Triticum aestivum L.)

Author(s):  
Leena Todkar ◽  
Harikrishna . ◽  
G. P. Singh ◽  
Neelu Jain ◽  
P. K. Singh ◽  
...  

The present study reports the introgression of the genomic regions linked with drought tolerance traits viz., NDVI, staygreen, chlorophyll content/chlorophyll fluorescence and yield from a drought tolerant parent HI1500 in to a popular high yielding but drought susceptible wheat variety GW322 following the marker assisted backcross breeding. Background selection with 109 polymorphic SSR markers accelerated genome recovery of recurrent parent which ranged from 72.14 to 86.9% in BC1F1, 90.33 to 92.02% in BC2F1 and 91.6 to 94.95% with an average of 93.5% in BC2F2 generation. Eighteen homozygous BC2F3 progenies were found to be phenotypically superior for morpho-physiological and agronomic traits over the recurrent parent GW322.

2018 ◽  
Vol 137 (4) ◽  
pp. 514-526 ◽  
Author(s):  
Neha Rai ◽  
Amasiddha Bellundagi ◽  
Prashant K. C. Kumar ◽  
Ramya Kalasapura Thimmappa ◽  
Sushma Rani ◽  
...  

Agriculture ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 64
Author(s):  
Priyanka Dwivedi ◽  
Naleeni Ramawat ◽  
Gaurav Dhawan ◽  
Subbaiyan Gopala Krishnan ◽  
Kunnummal Kurungara Vinod ◽  
...  

Reproductive stage drought stress (RSDS) is detrimental for rice, which affects its productivity as well as grain quality. In the present study, we introgressed two major quantitative trait loci (QTLs), namely, qDTY2.1 and qDTY3.1, governing RSDS tolerance in a popular high yielding non-aromatic rice cultivar, Pusa 44, through marker-assisted backcross breeding (MABB). Pusa 44 is highly sensitive to RSDS, which restricts its cultivation across drought-prone environments. Foreground selection was carried out using markers, RM520 for qDTY3.1 and RM 521 for qDTY2.1. Background selection was achieved with 97 polymorphic SSR markers in tandem with phenotypic selection to achieve faster recurrent parent genome (RPG) recovery. Three successive backcrosses followed by three selfings aided RPG recoveries of 98.6% to 99.4% among 31 near isogenic lines (NILs). Fourteen NILs were found to be significantly superior in yield and grain quality under RSDS with higher drought tolerance efficiency (DTE) than Pusa 44. Among these, the evaluation of two promising NILs in the multilocational trial during Kharif 2019 showed that they were significantly superior to Pusa 44 under reproductive stage drought stress, while performing on par with Pusa 44 under normal irrigated conditions. These di-QTL pyramided drought-tolerant NILs are in the final stages of testing the All India Coordinated Rice Improvement Project varietal trials for cultivar release. Alternately, the elite drought-tolerant Pusa 44 NILs will serve as an invaluable source of drought tolerance in rice improvement.


Plants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 2557
Author(s):  
Dilara Maslennikova ◽  
Oksana Lastochkina

We evaluated the effect of endobacteria Bacillus subtilis (strain 10–4) as a co-inoculant for promoting plant growth and redox metabolism in two contrasting genotypes of Triticum aestivum L. (wheat): Ekada70 (drought tolerant (DT)) and Salavat Yulaev (drought susceptible (DS)) in early stages of adaptation to drought (12% PEG–6000). Results revealed that drought reduced growth and dramatically augmented oxidative stress markers, i.e., hydrogen peroxide (H2O2) and lipid peroxidation (MDA). Furthermore, the depletion of ascorbate (AsA) and glutathione (GSH), accompanied by a significant activation of ascorbate peroxidase (APX) and glutathione reductase (GR), in both stressed wheat cultivars (which was more pronounced in DS genotype) was found. B. subtilis had a protective effect on growth and antioxidant status, wherein the stabilization of AsA and GSH levels was revealed. This was accompanied by a decrease of drought-caused APX and GR activation in DS plants, while in DT plants additional antioxidant accumulation and GR activation were observed. H2O2 and MDA were considerably reduced in both drought-stressed wheat genotypes because of the application of B. subtilis. Thus, the findings suggest the key roles in B. subtilis-mediated drought tolerance in DS cv. Salavat Yulaev and DT cv. Ekada70 played are AsA and GSH, respectively; which, in both cases, resulted in reduced cell oxidative damage and improved growth in seedlings under drought.


2018 ◽  
Vol 46 (2) ◽  
pp. 679-687 ◽  
Author(s):  
Preeyanuch LARKUNTHOD ◽  
Noppawan NOUNJAN ◽  
Jonaliza L SIANGLIW ◽  
Theerayut TOOJINDA ◽  
Jirawat SANITCHON ◽  
...  

Many of the economically important rice cultivars including ‘Khao Dawk Mali 105’ (KDML105) or jasmine rice, one of the world’s famous rice exported from Thailand suffers from drought due to erratic rainfalls and limited irrigation. To improve drought tolerance and reserve genetic background of KDML105, chromosome segment substitution lines (CSSL) containing drought tolerant quantitative trait loci (DT-QTL) has been previously developed by backcrossing between KDML105 and drought tolerant donor, IR58586-F2-CA-143 (DH212). To understand the physiological responses related to drought tolerance in CSSL lines compared to parents, two CSSLs namely CSSL1-16 and CSSL1-18, respectively were used in this study. Twenty-one-d-old hydroponically grown plants were subjected to 20% PEG for 0, 7, 14 d and then recovered from stress for 3 d. The results indicated that CSSL lines especially, CSSL1-16 showed better performance under drought stress compared to their recurrent parent. Drought tolerance superior CSSL1-16 line was indicated by high water status (high relative water content and leaf water potential), good osmotic adjustment, high proline and greater membrane stability. Moreover, this line was able to resume growth after stress recovery whereas other lines/cultivar could not recover. Similarly, drought tolerant donor showed high water status suggesting that well-maintained plant water status was associated with drought tolerant trait. It could be concluded that the highest drought tolerant line was CSSL1-16 followed by DH212, CSSL1-18 and KDML105. It would be interesting to go further into introgressed section in CSSL1-16 to identify potential candidate genes in DT-QTL for breeding drought tolerant rice in the future.


2018 ◽  
Vol 46 (1) ◽  
pp. 65-74 ◽  
Author(s):  
José F.T. GANANÇA ◽  
José G.R. FREITAS ◽  
Humberto G.M. NÓBREGA ◽  
Vanessa RODRIGUES ◽  
Gonçalo ANTUNES ◽  
...  

Taro [Colocasia esculenta (L.) Schott] is a root crop which is an important staple food in many regions of the world, producing 10.5 million tonnes on 1.4 million hectares a year. The crop is cultivated in wet (rain fed) or irrigated conditions, requiring on average 2,500 mm water per year, and in many countries it is cultivated in flooded plots. It is estimated that taro production could decrease by 40% as a result of the increase in drought and other severe events. In this work, thirty three accessions, including local cultivars, selected and hybrid lines were submitted to long duration drought stress and screened for tolerance. Twelve physiological, morphological and agronomic traits were measured at harvest, and subject to multivariate analysis. Stress indices, Water Use Efficiency and Factorial Analysis were useful for discriminating accessions regarding drought tolerance and yield stability, and drought tolerant and susceptible cultivars were identified. Our results confirm that different taro cultivars have different drought avoidance and tolerance strategies to cope with water scarcity. Better yield performers minimised biomass and canopy loss, while tolerance was observed in cultivars that presented low potential yield, but efficiently transferred resources to enhance corm formation. Among the 33 accessions, two local cultivars showed high yield stability and could be considered as suitable parents for breeding programs, while two others are well adapted to drought, but with overall low yield potential.


Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1411
Author(s):  
Samuel Chibuike Chukwu ◽  
Mohd Y. Rafii ◽  
Shairul Izan Ramlee ◽  
Siti Izera Ismail ◽  
Yusuff Oladosu ◽  
...  

The most vital aspect of marker-assisted backcross breeding is the recurrent parent genome recovery. This enables the selection of only parents with recovered recipient/recurrent parent genome in addition to the targeted genes. The recurrent parent genome recovery (RPGR) ensures that non-desirable genomic segments are removed while the gene of interest is sustained in the recombined progenies without further segregations. This work was aimed at quantifying the RPGR of backcross populations with introgression of bacterial leaf blight resistance genes. Putra-1, a Malaysian elite variety, high yielding with inherent resistance to blast but susceptible to bacterial leaf blight (BLB), was crossed with IRBB60 which is resistant to BLB disease. The IRBB60 has four Xoo resistance genes—Xa4, xa5, xa13 and Xa21. Tightly linked polymorphic functional and SSR markers were used for foreground selection at every stage of backcrossing to select progenies with introgressed target genes. Background selection was done to quantify the percentage of RPGR in the selected lines using 79 confirmed polymorphic microsatellites. Result obtained showed that the percentage of RPGR was 80.11% at BC1F1, 95.30% at BC2F1 and 95.9% at BC2F2. The introgression of Xa4, xa5, xa13 and Xa21 Xoo resistance genes were faster through the adopted marker-assisted backcross breeding compared to what could be obtained through conventional breeding. All the 16 selected lines displayed resistance to BLB with three lines showing high resistance to the disease. The blast resistance contained in the genetic background of Putra-1 was also sustained in all the selected lines. The newly developed lines were recommended as new rice varieties for commercial cultivation.


Biologia ◽  
2014 ◽  
Vol 69 (4) ◽  
Author(s):  
Zhijuan Ji ◽  
Jianyao Shi ◽  
Yuxiang Zeng ◽  
Qian Qian ◽  
Changdeng Yang

AbstractHybrid rice has contributed greatly to the self-sufficiency of the food supply in China. However, bacterial blight is a major disease that limits hybrid rice production in China. The study was conducted to develop an efficient breeding technique to improve the bacterial blight resistance in hybrid rice. A marker-assisted backcross breeding technique was adopted to improve HN189, an elite restorer line containing the Pi1 gene. This breeding technique was simplified to foreground selection with only one generation of backcrossing and background selection based on phenotypic selection. A novel bacterial blight resistance gene, Xa23, was introgressed into HN189. Two improved restorer lines, HBH145 (with one generation of backcrossing) and HBH146 (with two generations of backcrossing), were obtained that had a significant bacterial blight resistance advantage over HN189. The corresponding hybrid combination Tianyou H145 (Tianfeng A / HBH145) was certified one year earlier than Qianyou H146 (Qianjiang 1A / HBH146). The use of the marker-assisted backcross breeding technique with one generation of backcrossing and without background selection in rice breeding programs shortened the breeding period of the rice.


2021 ◽  
Vol 25 (05) ◽  
pp. 929-936
Author(s):  
Ruize Lin

Improving crop productivity under drought conditions contributes largely to the sustainable agriculture globally. In this study, the agronomic traits and physiological processes related to osmolyte accumulation and reactive oxygen species (ROS) homeostasis during late growth stage in wheat under drought stress were studied. Three cultivars viz., Shimai 22 (drought tolerant), Zhongxinmai 99 (median drought-tolerant, control), and Shi 4185 (drought sensitive) sharing contrasting drought tolerance were grown under normal irrigation (NI: with irrigations prior to sowing, and at jointing and flowering stages) and deficit irrigation (DI, with irrigations prior to sowing and at jointing) conditions. Data regarding yields, osmolyte (i.e., proline and soluble sugar) contents, and antioxidant enzyme activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD), and malondialdehyde (MDA) contents were recorded. Under deficit irrigation, the cultivars displayed modified agronomic and physiological traits. Among cultivars, Shimai 22 showed best agronomic traits (6.47 to 7.23% higher yield than control), osmolyte contents and AE activities (10.12 to 22.18% higher than control), and least MDA accumulation (12.30 to 17.06% lower than control). In contrast, Shi 4185 cultivar performed worst regarding above said traits. The transcripts of the genes in ��1-Pyrroline-5-carboxylate synthetase (P5CS) family that regulates proline biosynthesis and those in AE families that modulate ROS homeostasis were evaluated. Results revealed that the P5CS genes TaP5CS2 and TaP5CS5 and the AE ones TaSOD3, TaCAT2 and TaCAT5 were modified on transcripts across the cultivars under DI condition, showing to be significant upregulated compared with NI. These results suggested the essential roles of osmolyte accumulation and AE proteins in improving the drought tolerance of wheat during late growth stages. In addition, this study suggested that the elevated transcription efficiencies of distinct P5CS and AE family genes under water deprivation contribute to the enhanced drought tolerance in drought-tolerant cultivars. © 2021 Friends Science Publishers


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