scholarly journals Assessment of drought resistance in pearl millet (Pennisetum americanum (L.) Leeke). II. Estimation of genotype response to stress

1987 ◽  
Vol 38 (1) ◽  
pp. 49 ◽  
Author(s):  
FR Bidinger ◽  
V Mahalakshmi ◽  
GDP Rao

The finding that the more than 50% of the variation in grain yield of pearl millet breeding lines in two different drought stress treatments could be attributed to variation in yield potential and time of flowering was used to develop a drought-response index (DRI) based on the residual variation in grain yield, adjusted for experimental error. DRI was positively correlated to measured yield in the drought treatments, and independent of both yield potential and time to flowering. DRI in both midseason and terminal stress treatments was unrelated to yield component structure in the irrigated control treatment, indicating that selection for plant type under non-stressed conditions will not influence drought response. DRI was correlated to both grain number per panicle, and grain yield per panicle in both stress treatments, suggesting differential ability to maintain normal grain number, and/or that grain yield per panicle was an important factor in response to stress. Maintenance of panicle number did not seem to be important for maintenance of yield under drought stress. The correlation of DRI and individual panicle yield was of sufficient magnitude for the latter to serve as a selection index in terminal stress. The use of a DRI as a component of breeding for better adaptation to stress is discussed.

2021 ◽  
Vol 911 (1) ◽  
pp. 012002
Author(s):  
Muhammad Iqbal ◽  
Willy Bayuardi Suwarno ◽  
Muhammad Azrai

Abstract Climate change alters crop production in tropical and subtropical regions, and drought is a big challenge in maize production nowadays and near future. Breeding drought-tolerant varieties is important to keep production stability and food security. This research was undertaken to evaluate agronomic performance and yield potential of several maize genotypes in a drought stress environment, and to identify potential genotypes for further utilization in a maize breeding program. The experiment was conducted using an augmented design with 370 test genotypes and 6 checks at Sukoharjo Village, Kediri, East Java, from September 2014 to January 2015. The plants suffered from drought stress in the pre-anthesis period. Results of the analysis of variance showed that the effect of genotype is significant on grain yield, ear yield, plant height, and ear height. Linear correlation analysis showed that grain yield is negatively correlated with leaf senescence. Selection for tolerant genotypes was conducted using selection index and cluster analysis. Line 249 and 252 are considered potential for subsequent breeding processes because they have similar traits with a formerly known drought-tolerant variety, namely Bima 19URI.


2018 ◽  
Vol 16 (4) ◽  
pp. 378-385 ◽  
Author(s):  
C. O. Anyaoha ◽  
M. Fofana ◽  
V. E. Gracen ◽  
P. B. Tongoona ◽  
E. T. Blay ◽  
...  

AbstractThe goal of most rice improvement programs is the enhancement of farmers’ yield using less land and limited water. This study evaluated 77 upland rice genotypes under optimal upland growing conditions in the field and ranked the genotypes using base indices. Subsequently, eighteen cultivars selected from the field trial were screened under drought in rainout-shelter conditions. The traits evaluated for index selection were yield, days to flowering, plant height, number of panicles and filled grains. Under field conditions, based on the sum of economic weight assigned to five traits used to compute the selection index, IR 68704-145-1-1-B and IR 63380-16 were the best genotypes. In the rainout-shelter experiment, Ofada 2 (508 gm−2) had the highest grain yield under non-stress conditions while ITA 117 (152.38 gm−2) had the highest grain yield under drought stress. The base index was efficient for selecting superior genotypes with the best combination for all the traits considered. Susceptibility to drought stress of the landraces leads to poor grain yield.


2000 ◽  
Vol 80 (4) ◽  
pp. 739-745 ◽  
Author(s):  
B. L. Duggan ◽  
D. R. Domitruk ◽  
D. B. Fowler

Crops produced in the semiarid environment of western Canada are subjected to variable and unpredictable periods of drought stress. The objective of this study was to determine the inter-relationships among yield components and grain yield of winter wheat (Triticum aestivum L) so that guidelines could be established for the production of cultivars with high yield potential and stability. Five hard red winter wheat genotypes were grown in 15 field trials conducted throughout Saskatchewan from 1989–1991. Although this study included genotypes with widely different yield potential and yield component arrangements, only small differences in grain yield occurred within trials under dryland conditions. High kernel number, through greater tillering, was shown to be an adaptation to low-stress conditions. The ability of winter wheat to produce large numbers of tillers was evident in the spring in all trials; however, this early season potential was not maintained due to extensive tiller die-back. Tiller die-back often meant that high yield potential genotypes became sink limiting with reduced ability to respond to subsequent improvements in growing season weather conditions. As tiller number increased under more favourable crop water conditions genetic limits in kernels spike−1 became more identified with yield potential. It is likely then, that tillering capacity per se is less important in winter wheat than the development of vigorous tillers with numerous large kernels spike−1. For example, the highest yielding genotype under dryland conditions was a breeding line, S86-808, which was able to maintain a greater sink capacity as a result of a higher number of larger kernels spike−1. It appears that without yield component compensation, a cultivar can be unresponsive to improved crop water conditions (stable) or it can have a high mean yield, but it cannot possess both characteristics. Key words: Triticum aestivum L., wheat, drought stress, kernel weight, kernel number, spike density, grain yield


Plants ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 518 ◽  
Author(s):  
Nelimor ◽  
Badu-Apraku ◽  
Tetteh ◽  
N’guetta

Climate change is expected to aggravate the effects of drought, heat and combined drought and heat stresses. An important step in developing ‘climate smart’ maize varieties is to identify germplasm with good levels of tolerance to the abiotic stresses. The primary objective of this study was to identify landraces with combined high yield potential and desirable secondary traits under drought, heat and combined drought and heat stresses. Thirty-three landraces from Burkina Faso (6), Ghana (6) and Togo (21), and three drought-tolerant populations/varieties from the Maize Improvement Program at the International Institute of Tropical Agriculture were evaluated under three conditions, namely managed drought stress, heat stress and combined drought and heat stress, with optimal growing conditions as control, for two years. The phenotypic and genetic correlations between grain yield of the different treatments were very weak, suggesting the presence of independent genetic control of yield to these stresses. However, grain yield under heat and combined drought and heat stresses were highly and positively correlated, indicating that heat-tolerant genotypes would most likely tolerate combined drought and stress. Yield reduction averaged 46% under managed drought stress, 55% under heat stress, and 66% under combined drought and heat stress, which reflected hypo-additive effect of drought and heat stress on grain yield of the maize accessions. Accession GH-3505 was highly tolerant to drought, while GH-4859 and TZm-1353 were tolerant to the three stresses. These landrace accessions can be invaluable sources of genes/alleles for breeding for adaptation of maize to climate change.


Agronomy ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 591 ◽  
Author(s):  
Liu ◽  
Zhan ◽  
Hussain ◽  
Nie

Aerobic rice has the potential to replace transplanted flooded rice, as rice cultivation is seriously threatened by environmental and social factors. Although the recently released upland rice cultivars have higher drought tolerance, low yield potential of these cultivars makes them less feasible for high-yielding rice planting regions under aerobic cultivation. In this study, typical lowland rice cultivars (Huanghuazhan and Yangliangyou6) were evaluated for grain yield and resource use efficiencies under aerobic cultivation as compared with upland rice cultivars (Lvhan1 and Hanyou3). Averaged across different years, lowland rice cultivars recorded 26.9%, 14.6%, and 26.6% higher grain yield, water productivity, and nitrogen use efficiency for grain production (NUEg), respectively, as compared with upland cultivars. The higher grain yield of lowland rice cultivars under aerobic cultivation was mainly attributed to the higher aboveground biomass and the spikelet number per panicle, along with a higher harvest index and panicle number per unit area with respect to upland rice cultivars. During the entire growing season in aerobic cultivation, rainfall accounted for 60% to 85% of the total water use, which indicates that lowland rice cultivars could make better use of the rainfall because of a longer growth duration and a higher growth potential. In summary, this study suggests that with appropriate irrigation, lowland rice cultivars could grow well and furnish higher yield than the current upland rice cultivars under aerobic cultivation.


Agriculture ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 167 ◽  
Author(s):  
Kifayatullah Kakar ◽  
Tran Dang Xuan ◽  
Saidajan Abdiani ◽  
Imran Khan Wafa ◽  
Zubair Noori ◽  
...  

Rice is an important staple food for Afghans. Its production has been increased, and attention is needed to improve grain quality. Experiments were conducted to evaluate the growth, yield, physicochemical properties, antioxidant activity, and morphological structures of four exotic rice varieties widely grown in Afghanistan (Attai-1, Jalalabad-14, Shishambagh-14, and Zodrass). Antioxidant activities, including 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS), of rice grain were determined. A scanning electron microscopic observation was conducted on the cross-cut section of dehulled rice grains. The results showed a wide variation among four rice varieties for growth, grain yield, physicochemical properties, antioxidant activities, and morphology. Tiller and panicle number per hill, 1000-grain weight, grain yield, and antioxidant activities were found to be highest in Jalalabad-14. Attai-1 showed lower amylose, protein, and lipid contents with a high number of perfect grains, consequently enhanced taste point (score of quality). Grain yield, protein, and amylose contents showed a negative correlation with antioxidant activities. Accumulated structures in Attai-1, Shishambagh-14, and Zodrass were normal; however, Jalalabad-14 increased protein bodies and its traces in the amyloplasts. Information on yield potential, grain quality, and nutritional value of these exotic rice varieties may useful for sustainable food provision and nutritional improvement of rice in Afghanistan.


Author(s):  
P. Choudhary ◽  
S. K. Payasi ◽  
N. K. Patle

Mungbean (Vigna radiata L.) genotypes along with two parents were studied to assess the magnitude of genotypic variability, heritability and selection indices among the yield components and their direct and indirect effects on grain yield. On the basis of genetic variability, all the traits exhibited high heritability estimates coupled with high genetic advance as percent of mean (h2³ 60%, GAM³20 %) except 100 grain weight (h2 = 0.51, GAM= 8.0 %), indicating the preponderance of additive gene action. Biological yield/plant and harvest index had the most positive direct effects (1.448, 1.144, respectively) on grain yield/plant, indicating these traits synergistically affect photosyntates. Based on Smith-Hazel indices the highest genetic advance (17.56%) in grain yield/plant obtained on linear combination of traits such as days to 50% flowering, days to maturity, plant height, pod length, grains/pod and biological yield/plant (X2X3X4X7X8X10) accomplished through a completely new selection-index in which economic weight of each traits were equally distributed, suggesting that these parameters may be considered as prime traits during the course of selection to realize higher yield potential in green gram.


2013 ◽  
Vol 145 ◽  
pp. 106-115 ◽  
Author(s):  
Daniela V. Bustos ◽  
Ahmed K. Hasan ◽  
Matthew P. Reynolds ◽  
Daniel F. Calderini

Author(s):  
Özgür Tatar ◽  
Uğur Çakaloğullari ◽  
Gülden Deniz Ateş Atasoy ◽  
Deniz Iştipliler

AbstractWheat, being the main crop in Mediterranean type environments, is grown during winter under rainfed conditions and its yield potential is mostly affected by the amount and distribution of rain. This study is conducted at experimental fields of Ege University, Department of Field Crops in Izmir-Bornova which is characterized as Mediterranean type climate conditions during 2011/2012 and 2012/2013 growing season. Totally 9 canopy structures were generated by different row and line distances. Plant height, total dry weight, tiller number, harvest index, spike number, grain number per spike, thousand grain weight and grain yield were determined after harvest time while digital leaf area index and soil moisture contents were monitoring during specific growth periods to evaluate changes in soil water status by different canopy closer. Increasing in sowing density by different row and in-line distance reduced tiller and spike number per plant. On the other hand, grain number per spike and thousand grain weights were significantly affected by in-line distance instead of row distance. Higher grain yield were obtained from 20x1 cm treatments. Canopy cover speed determined using with digital imaging was not remarkable correlated (r=0.06) with soil moisture content during post-anthesis stage of wheat when higher rain amount is recorded in 2012. However, there was a significant negative correlation (r=0.51) between canopy cover speed and soil water status during post-anthesis stage when the rain amount is limited in 2013. We may suggest that rapid canopy cover lead to negative effect on soil water status via higher transpiration if the rain is limited during post-anthesis stage of wheat.


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