FIELD EVALUATION OF TISSUE CULTURE DERIVED SORGHUM FOR INCREASED TOLERANCE TO ACID SOILS AND DROUGHT STRESS

1990 ◽  
Vol 70 (4) ◽  
pp. 997-1004 ◽  
Author(s):  
R. M. WASKOM ◽  
D. R. MILLER ◽  
G. E. HANNING ◽  
R. R. DUNCAN ◽  
R. L. VOIGT ◽  
...  

Plant tissue culture is being recognized as an important tool for generating useful variants for crop improvement. The objective of this research was to determine if improved tolerance to acid soil and drought stress can be generated in sorghum [Sorghum bicolor (L.) Moench] through tissue culture. Two environments were used to screen for enhanced field tolerance: (1) a low pH field in Griffin, Georgia for testing acid soil stress tolerance, and (2) an arid environment in Yuma, Arizona for testing drought stress tolerance. A population of 212 R1 sorghum lines from tissue cultures of Hegari and Tx430 were increased in 1986. Screening was then conducted in both environments during 1987. Selected entries which showed improved tolerance were advanced and re-tested during 1988. From this original population, four lines were identified as having improved acid soil tolerance and five lines were identified as having improved drought tolerance as compared to the non-regenerated checks. Three of these lines performed better than the non-regenerated checks under both acid soil and drought stress conditions. These results indicate that somaclonal variants for increased tolerance to environmental stresses can be generated in tissue culture and be selected under proper field conditions.Key words: Sorghum bicolor, somaclonal variation, drought tolerance, acid soil tolerance, tissue culture

2020 ◽  
Vol 80 (01) ◽  
Author(s):  
Bhupender Kumar ◽  
Krishan Kumar ◽  
Shankar Lal Jat ◽  
Shraddha Srivastava ◽  
Tanu Tiwari ◽  
...  

Drought stress is the major production constraint in rainfed maize. Screening for drought tolerance is severely affected by the lack of a simple and reliable phenotyping technique. The objective of this study was to standardize a simple hydroponic based drought screening technique in maize. In this context, one week old uniform seedlings of 55 inbreds and 5 hybrids were transferred to hydroponic solution in the glass house. The seedlings were allowed to acclimatize for next one week in hydroponic solution. The drought stress was imposed by removing seedlings from nutrient solution and exposed to air for 6 and 4 hours daily for a period of 5 and 4 consecutive days in hybrids and inbreds, respectively. Data were recorded on all shoot and root parameters, and based on stress symptoms, a drought tolerance score was given to each genotype. The percent deductions in shoot and root fresh weight from non-stress to stress ranged from 11.7 to 84.4 and 2.1 to 77.5, respectively. Six inbred lines, namely, DQL790-4, CML334, CM140, CML422, CM125 and HKI488 and three hybrids namely DMRH1306, DMRH1410 and PMH4 were found drought tolerant. The effectiveness of this screening technique was compared and confirmed using pots screening as well as by expression profiling of key antioxidant genes (Sod2, Sod4, Sod9 and Apx1) playing role in drought stress tolerance. This phenotyping technique is very short, low cost and simple which can be utilized in preliminary drought screening for large set of maize germplasm and mapping populations.


Author(s):  
Pardeep Kumar ◽  
Mukesh Choudhary ◽  
B. S. Jat ◽  
M. C. Dagla ◽  
Vishal Singh ◽  
...  

Abstract This chapter focuses on target traits for drought stress, progress in mapping for drought tolerance-associated genes/QTLs identification and expression studies and introgression strategies followed by the possibilities of integrating the concept of speed breeding in maize drought breeding programmes for better utilization of wild relatives.


2017 ◽  
Vol 16 (4) ◽  
pp. 289-295 ◽  
Author(s):  
Kumari Neelam ◽  
Gurpreet K. Sahi ◽  
Kishor Kumar ◽  
Kuldeep Singh

AbstractDrought is the major abiotic constraint to the rice production in the rain-fed areas across Asia and sub-Saharan Africa. Wild species of Oryza offer a wide spectrum of adaptive traits and can serve as potential donors of biotic and abiotic stress tolerance. At the Punjab Agricultural University, we are maintaining an active collection of 1630 accessions of wild species germplasm (AA, CC, BBCC and CCDD) of rice. These accessions were screened to assess genetic variation for drought tolerance under field conditions. Severe water stress was imposed at the late vegetative stage by withholding water initially for 25 d and then extended further to 35 d during kharif season in the years 2013–14 and 2015–16. The tolerance score for drought stress was based on the extent of leaf rolling and leaf drying. Based on the 2 years’ data, seven accessions from Oryza rufipogon, four from Oryza longistaminata and one each from Oryza officinalis and Oryza latifolia were found tolerant to drought stress. These selected accessions were further phenotype for root morphology. The average root length among the selected accessions ranges between 36 and 80 cm and the number of primary roots vary from 30 to 87 cm. The O. rufipogon accession IRGC 106433, O. longistaminata accession IRGC 92656A, O. officinalis accession IRGC 101152 and O. latifolia accession IRGC 80769 showed approximately 2–2.5 times longer root length and number than the indica rice elite cultivar PR121. The results indicated potentiality of selected wild species germplasm for conferring drought tolerance to the elite cultivars.


1991 ◽  
pp. 1081-1093 ◽  
Author(s):  
C. I. Flores ◽  
L. M. Gourley ◽  
J. F. Pedersen ◽  
R. B. Clark

2022 ◽  
Vol 46 (1) ◽  
Author(s):  
Almoataz Bellah Ali El-Mouhamady ◽  
Abdul Aziz M. Gad ◽  
Ghada S. A. Abdel Karim

Abstract Background Water stress, specifically the limited water resources needed to grow strategic crops, especially rice, poses a great threat to crop productivity. So, it was imperative that scientists all work together to try genetically improving the rice for drought tolerance in light of these environmental challenges. The aim of this study is trying to know the genetic behavior responsible for water-deficit tolerance in rice genotypes but at the molecular level. Moreover, this attempt will be an important leap in the process of genetic improvement in rice for water stress tolerance in Egypt. Results Twenty-three rice genotypes including eight parents and their fifteen F1 crosses or (the first hybrid generation) by line X tester analysis were evaluated for water stress tolerance during two experiments (the control and drought experiment) besides some molecular–biochemical studies for eight parents and the highest selected five crosses for water stress tolerance. The research revealed that five rice crosses out of fifteen hybrids were highly tolerant to water stress compared to the normal conditions. Data of biochemical markers indicated the presence of bands that are considered as molecular genetic markers for water-deficit tolerance in some rice genotypes, and this is the scientific progress achieved in this research. This was evident by increasing the density and concentration of SDS-protein electrophoresis besides enhancing the activities of peroxidase (POD) and polyphenol oxidase (PPO) under water-deficit conditions, which confirmed the tolerance of drought stress in the eight rice genotypes and the best five crosses from the first hybrid generation. Conclusion The five promising and superior rice hybrids showed an unparalleled tolerance to water stress in all evaluated traits under water stress treatment compared to the standard experiment. Also, biochemical and molecular parameters evidence confirmed the existence of unquestionable evidence that it represents the main nucleus for producing rice lines tolerated for drought stress under Egyptian conditions.


2021 ◽  
Vol 12 ◽  
Author(s):  
Juan Carlos Suárez ◽  
Milan O. Urban ◽  
Amara Tatiana Contreras ◽  
Jhon Eduar Noriega ◽  
Chetan Deva ◽  
...  

In our study, we analyzed 30years of climatological data revealing the bean production risks for Western Amazonia. Climatological profiling showed high daytime and nighttime temperatures combined with high relative humidity and low vapor pressure deficit. Our understanding of the target environment allows us to select trait combinations for reaching higher yields in Amazonian acid soils. Our research was conducted using 64 bean lines with different genetic backgrounds. In high temperatures, we identified three water use efficiency typologies in beans based on detailed data analysis on gasometric exchange. Profligate water spenders and not water conservative accessions showed leaf cooling, and effective photosynthate partitioning to seeds, and these attributes were found to be related to higher photosynthetic efficiency. Thus, water spenders and not savers were recognized as heat resistant in acid soil conditions in Western Amazonia. Genotypes such as BFS 10, SEN 52, SER 323, different SEFs (SEF 73, SEF 10, SEF 40, SEF 70), SCR 56, SMR 173, and SMN 99 presented less negative effects of heat stress on yield. These genotypes could be suitable as parental lines for improving dry seed production. The improved knowledge on water-use efficiency typologies can be used for bean crop improvement efforts as well as further studies aimed at a better understanding of the intrinsic mechanisms of heat resistance in legumes.


1991 ◽  
pp. 1037-1045
Author(s):  
R. R. Duncan ◽  
R. E. Wilkinson ◽  
L. M. Shuman ◽  
E. L. Ramseur

2007 ◽  
Vol 19 (3) ◽  
pp. 193-201 ◽  
Author(s):  
Marcelo de A. Silva ◽  
John L. Jifon ◽  
Jorge A.G. da Silva ◽  
Vivek Sharma

Drought is one of the major limitations to plant productivity worldwide. Identifying suitable screening tools and quantifiable traits would facilitate the crop improvement process for drought tolerance. In the present study, we evaluated the ability of four relatively physiological parameters (variable-to-maximum chlorophyll a fluorescence ratio, F v/F m; estimated leaf chlorophyll content via SPAD index; leaf temperature, LT; and, leaf relative water content, RWC) to distinguish between drought tolerant and susceptible sugarcane genotypes subjected to a 90-d drought cycle. Eight field-grown genotypes were studied. By 45 d after the onset of treatments, the F v/F m, SPAD index and RWC of drought-stressed plants had declined significantly in all genotypes compared to values at the onset of well-watered treatments. However, the reductions were more severe in leaves of susceptible genotypes. Under drought stress, the tolerant genotypes as a group, maintained higher F v/F m (8%), SPAD index (15%), and RWC (16%) than susceptible genotypes. In general, LT of drought-stressed plants was higher (~4ºC) than that of well-watered plants but the relative increase was greater among drought susceptible genotypes. Under drought stress, LT of tolerant genotypes was on average 2.2ºC lower than that of susceptible genotypes. The results are consistent with the tolerant-susceptible classification of these genotypes and indicate that these tools can be reliable in screening for drought tolerance, with F v/F m, SPAD index and LT having the added advantage of being nondestructive and easily and quickly assessed.


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