scholarly journals Effect of drought stress during grain filling in near-isogenic tall and dwarf hybrids of pearl millet (Pennisetum glaucum)

1991 ◽  
Vol 116 (1) ◽  
pp. 67-72 ◽  
Author(s):  
V. Mahalakshmi ◽  
F. R. Bidinger ◽  
D. S. Raju

SUMMARYThe susceptibility to drought stress during flowering and grain filling of dwarf hybrids of pearl millet carrying the dwarfing gene d2 was investigated in 1987 at Patancheru, India, under field conditions during the dry season and, in the rainy season, under a rain shelter, using four pairs of near-isogenic tall and dwarf hybrids. Drought stress during grain filling reduced the number of grains per unit area and individual grain mass. Grain yields of the dwarf hybrids were lower than those of the corresponding tall hybrids in the unstressed control and under drought stress and were associated with a lower individual grain mass in the dwarf lines. In the dwarf hybrids, harvest index was similar to or better than that of the tall versions but a reduced biomass resulted in lower grain yields. Dwarf hybrids were not more adversely affected by water stress, however, than their tall counterparts, indicating that susceptibility to drought stress would not be likely to limit acceptance of new dwarf varieties.

2020 ◽  
Vol 12 (14) ◽  
pp. 5610
Author(s):  
Alireza Pour-Aboughadareh ◽  
Reza Mohammadi ◽  
Alireza Etminan ◽  
Lia Shooshtari ◽  
Neda Maleki-Tabrizi ◽  
...  

Durum wheat performance in the Mediterranean climate is limited when water scarcity occurs before and during anthesis. The present research was performed to determine the effect of drought stress on several physiological and agro-morphological traits in 17 durum wheat genotypes under two conditions (control and drought) over two years. The results of analysis of variance indicated that the various durum wheat genotypes responded differently to drought stress. Drought stress significantly reduced the grain filling period, plant height, peduncle length, number of spikes per plot, number of grains per spike, thousand grains weight, grain yield, biomass, and harvest index in all genotypes compared to the control condition. The heatmap-based correlation analysis indicated that grain yield was positively and significantly associated with phenological characters (days to heading, days to physiological maturity, and grain filling period), as well as number of spikes per plant, biomass, and harvest index under drought conditions. The yield-based drought and susceptible indices revealed that stress tolerance index (STI), geometric mean productivity (GMP), mean productivity (MP), and harmonic mean (HM) were positively and significantly correlated with grain yields in both conditions. Based on the average of the sum of ranks across all indices and a three-dimensional plot, two genotypes (G9 and G12) along with the control variety (G1) were identified as the most tolerant genotypes. Among the investigated genotypes, the new breeding genotype G12 showed a high drought tolerance and yield performance under both conditions. Hence, this genotype can be a candidate for further multi-years and locations test as recommended for cultivation under rainfed conditions in arid and semi-arid regions.


2015 ◽  
Vol 3 (1) ◽  
pp. 134-138 ◽  
Author(s):  
Minakshi Choudhary ◽  
Jayanand Manjhi ◽  
Anvesha Sinha

Introduction: Pearl millet (Pennisetum glaucum) is an important cereal of traditional farming systems that has the natural ability to withstandvarious abiotic stresses such as drought, which is one of the most important manifestations of abiotic stress in plants. These plants havehowever evolved mechanisms that allow them to adapt and survive prolonged periods of water deficit at some level or form of plant structure,if not at the whole plant level. The hostile conditions augment the formation of reactive oxygen species (ROS) during physiological stresses inplants which are combated by various enzymatic and non-enzymatic mechanisms. The present study aims at examining the role of fourimportant enzymes namely Ascorbic peroxidase (APX), Peroxidase (POX), Catalase (CAT) and Superoxide Dismutase(SOD) expressed duringdrought stress in pearl millet (Pennisetum glaucum). Method: 12 and 22 days old seedlings of Pennisetum cultivar HHB-68 were subjectedto drought stress by treatment of 30% Polyethylene glycol for different time periods 30min (T1), 2hr (T2), 4hr (T3), 8hr (T4), 16hr (T5), 24hr(T6) and 48hr (T7) respectively, monitored by examining RWC of seedlings. The treatment seedlings were then used for investigating thelevels of enzymes activity in response to prolonged dehydration periods of 22 days. The enzyme activity of POX, APX, CAT and SOD wereassayed. Result: Enzymes expression was assayed for each treatment sets at both time intervals. Drought stress was observed to causeremarkable increase in POX, APX and SOD activity while incidence of CAT enzyme decreased with the increasing period of water deficit.Conclusion: Prolonged periods of water deficiency causes significant variations in expression of various enzymes in Pennisetum glaucum,known to be involved in ROS scavenging and drought stress management. The study provides a sturdy validation of the role of these enzymesas potent mechanisms undertaken by drought resistant plants for successful management of drought stress, which can be used for thedevelopment of more efficient and economic drought resistant cultivars.DOI: http://dx.doi.org/10.3126/ijasbt.v3i1.12278       Int J Appl Sci Biotechnol, Vol. 3(1): 134-138 


1993 ◽  
Vol 29 (1) ◽  
pp. 121-129 ◽  
Author(s):  
K. C. Reddy ◽  
P. L. Visser

SummaryThe performance of two contrasting pearl millet (Pennisetum glaucum) genotypes was compared following five planting dates under rainfed conditions in deep sandy soils at Bengou, Niger in 1986 and 1987. The early and partially photo-sensitive cultivar HKB yielded more grain than the late and photo-sensitive cultivar Somno when planted with the first two seasonal rains. But after delayed planting, the crop growth rate and harvest index of cultivar HKB were reduced, leading to smaller grain yields even though the growth period, rainfall, radiation and temperature were similar at all the planting dates. In contrast, cultivar Somno maintained a small but stable harvest index over various planting dates, so that although its growth period and crop growth rate were reduced by delayed planting, the reduction in grain yield was less. Since agronomic manipulation, such as increased plant density and fertilizer application, can be used to increase crop growth rate, photo-sensitive millet genotypes such as cultivar Somno could be used for late July plantings in the Sudano-Sahelian zone.


2014 ◽  
Vol 41 (11) ◽  
pp. 1138 ◽  
Author(s):  
Gorka Erice ◽  
Alvaro Sanz-Sáez ◽  
Amadeo Urdiain ◽  
Jose L. Araus ◽  
Juan José Irigoyen ◽  
...  

Despite its relevance, few studies to date have analysed the role of harvest index (HI) in the responsiveness of wheat (Triticum spp.) to elevated CO2 concentration ([CO2]) under limited water availability. The goal of the present work was to characterise the role of HI in the physiological responsiveness of durum wheat (Triticum durum Desf.) exposed to elevated [CO2] and terminal (i.e. during grain filling) water stress. For this purpose, the performance of wheat plants with high versus low HI (cvv. Sula and Blanqueta, respectively) was assessed under elevated [CO2] (700 μmol mol–1 vs 400 μmol mol–1 CO2) and terminal water stress (imposed after ear emergence) in CO2 greenhouses. Leaf carbohydrate build-up combined with limitations in CO2 diffusion (in droughted plants) limited the responsiveness to elevated [CO2] in both cultivars. Elevated [CO2] only increased wheat yield in fully watered Sula plants, where its larger HI prevented an elevated accumulation of total nonstructural carbohydrates. It is likely that the putative shortened grain filling period in plants exposed to water stress also limited the responsiveness of plants to elevated [CO2]. In summary, our study showed that even under optimal water availability conditions, only plants with a high HI responded to elevated [CO2] with increased plant growth, and that terminal drought constrained the responsiveness of wheat plants to elevated [CO2].


2012 ◽  
Vol 30 (3) ◽  
pp. 137-145 ◽  
Author(s):  
Bruce L. Dunn ◽  
Janet C. Cole ◽  
Mark E. Payton

Experiments were conducted to evaluate potential means for reducing moisture stress in nine herbaceous and woody ornamental species. In Expt. 1 (2009), a water only control treatment and the antitranspirant Stasis™ at two different rates were applied as a drench application before inducing drought stress in the greenhouse by withholding water for two weeks. No significant differences in visual ratings in relation to plant quality were detected among treatments 5 days after application for any species. At 10 days after treatment, visual ratings were better for Veronica at the lower Stasis™ rate, Hibiscus at the low and higher Stasis™ rate, and Weigela at lower and higher Stasis™ rate compared to no Stasis™. At 15 days after treatment, visual ratings were worse for Coreopsis, Rudbeckia, and Salvia at both low and high Stasis™ rates; but, were better for Hibiscus and Weigela at the lower and higher Stasis™ rates compared to the no Stasis™ treatment. In Expt. 2 (2010), the antitranspirants Stasis™ and Root-Zone were evaluated along with a no antitranspirant and well-watered control treatments at single rates. No significant differences in visual ratings existed among treatments five days after application for any species. At 10 days after treatment, visual ratings were higher for Coreopsis, Forsythia, Nandina, and Weigela with Stasis™ or Root-Zone compared to no antitranspirant application. Visual ratings for Rudbeckia and Salvia with Stasis™, and Euonymus with Root-Zone were also better than the stress treatment at 10 days after treatment. At 15 days after treatment, visual ratings were higher for Coreopsis and Salvia with Stasis™ compared to the stress treatment. Rudbeckia, Euonymus, and Weigela with Stasis™ or Root-Zone and Nandina with Root-Zone all had better visual ratings than the stress treatment. Evapotranspiration was not reduced for any Stasis™ or Root-Zone treatment for any species in either experiment compared to control stress treatments.


1988 ◽  
Vol 110 (1) ◽  
pp. 71-79 ◽  
Author(s):  
P. Q. Craufurd ◽  
F. R. Bidinger

SummaryThe phenotype of medium duration pearl millet varieties grown in West Africa differs from that of the shorter duration millets grown in India. African varieties are usually much taller, have longer panicles, fewer productive tillers, and a lower ratio of grain to above-ground dry-matter (harvest index). The effect of crop duration on plant phenotype was investigated in two hybrids using extended daylengths to increase the duration of the vegetative phase (GSl: sowing to panicle initiation). The two hybrids, 841A × J104 and 81A × Souna B, were considered to represent the Indian and African phenotype, respectively. Tiller production and survival, leaf area, and dry-matter accumulation and partition, were monitored over the season. Grain yield and its components were determined at maturity.The two hybrids responded similarly to the short and long daylength treatments. The duration of GSl was increased from 20 to 30 days, resulting in increased number of leaves, leaf area, and stem and total dry-matter accumulation; there was no effect on tiller production and survival, or on panicle growth rate. Grain yield was, therefore, the same in both GSl treatments, and harvest index (HI) was much reduced in the long GSl treatment owing to the increased stem growth. One evident effect of a longer GSl was on dry-matter partitioning between shoots; partitioning to the main stem (MS) was increased, whereas partitioning to the tillers was reduced.There was no difference in crop development, growth or yield between the two hybrids in either GSl treatment. The only significant differences were in the efficiency with which intercepted radiation was converted to dry matter, which was greater in 841A × J104 than in 81A × Souna B, and in the balance between MS and tillers; the grain yield of the MS was significantly greater in 81A x Souna B than in 841A × J104, but at the expense of number of productive tillers.The results demonstrate that both African and Indian phenotypes are equally productive under good agronomic conditions. The lower HI in longer duration African millets is a consequence of a much extended stem growth phase and therefore increased competition between stem and panicle during grain filling. Possible ways to increase grain yield in the medium duration African millets are considered.


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