Genetic variability in high temperature effects on seed-set in sorghum

2013 ◽  
Vol 40 (5) ◽  
pp. 439 ◽  
Author(s):  
Chuc T. Nguyen ◽  
Vijaya Singh ◽  
Erik J. van Oosterom ◽  
Scott C. Chapman ◽  
David R. Jordan ◽  
...  

Sorghum (Sorghum bicolor (L.) Moench) is grown as a dryland crop in semiarid subtropical and tropical environments where it is often exposed to high temperatures around flowering. Projected climate change is likely to increase the incidence of exposure to high temperature, with potential adverse effects on growth, development and grain yield. The objectives of this study were to explore genetic variability for the effects of high temperature on crop growth and development, in vitro pollen germination and seed-set. Eighteen diverse sorghum genotypes were grown at day : night temperatures of 32 : 21°C (optimum temperature, OT) and 38 : 21°C (high temperature, HT during the middle of the day) in controlled environment chambers. HT significantly accelerated development, and reduced plant height and individual leaf size. However, there was no consistent effect on leaf area per plant. HT significantly reduced pollen germination and seed-set percentage of all genotypes; under HT, genotypes differed significantly in pollen viability percentage (17–63%) and seed-set percentage (7–65%). The two traits were strongly and positively associated (R2 = 0.93, n = 36, P < 0.001), suggesting a causal association. The observed genetic variation in pollen and seed-set traits should be able to be exploited through breeding to develop heat-tolerant varieties for future climates.

2012 ◽  
Vol 39 (12) ◽  
pp. 1009 ◽  
Author(s):  
Viola Devasirvatham ◽  
Pooran M. Gaur ◽  
Nalini Mallikarjuna ◽  
Raju N. Tokachichu ◽  
Richard M. Trethowan ◽  
...  

High temperature during the reproductive stage in chickpea (Cicer arietinum L.) is a major cause of yield loss. The objective of this research was to determine whether that variation can be explained by differences in anther and pollen development under heat stress: the effect of high temperature during the pre- and post-anthesis periods on pollen viability, pollen germination in a medium, pollen germination on the stigma, pollen tube growth and pod set in a heat-tolerant (ICCV 92944) and a heat-sensitive (ICC 5912) genotype was studied. The plants were evaluated under heat stress and non-heat stress conditions in controlled environments. High temperature stress (29/16°C to 40/25°C) was gradually applied at flowering to study pollen viability and stigma receptivity including flower production, pod set and seed number. This was compared with a non-stress treatment (27/16°C). The high temperatures reduced pod set by reducing pollen viability and pollen production per flower. The ICCV 92944 pollen was viable at 35/20°C (41% fertile) and at 40/25°C (13% fertile), whereas ICC 5912 pollen was completely sterile at 35/20°C with no in vitro germination and no germination on the stigma. However, the stigma of ICC 5912 remained receptive at 35/20°C and non-stressed pollen (27/16°C) germinated on it during reciprocal crossing. These data indicate that pollen grains were more sensitive to high temperature than the stigma in chickpea. High temperature also reduced pollen production per flower, % pollen germination, pod set and seed number.


2019 ◽  
Vol 157 (04) ◽  
pp. 283-299 ◽  
Author(s):  
C. Malumpong ◽  
S. Cheabu ◽  
C. Mongkolsiriwatana ◽  
W. Detpittayanan ◽  
A. Vanavichit

AbstractThe reproductive stage of rice is the most sensitive to heat stress, which can lead to spikelet sterility. Thus, heat-tolerant and heat-susceptible genotypes were used to investigate their differences in terms of phenotypic responses and expression changes of Hsf genes at the pre-flowering stage under heat stress. Results clearly showed that panicles had the highest temperature compared with other plant parts under both natural and heated conditions. However, the temperatures of tolerant and susceptible genotypes were not significantly different. In terms of spikelet fertility, the tolerant lines M9962 and M7988 had high seed set because their anther dehiscence, pollen viability and pollen germination were only slightly affected. In contrast, the susceptible line Sinlek showed severe effects at all steps of fertilization, and the pollen viability of M7766 was slightly affected under heat stress but was more affected in terms of anther dehiscence and pollen germination. Both susceptible lines showed dramatically decreased seed set. In addition, the expression of six HsfA genes in the flag leaves and spikelets at the R2 stage of plants under heat stress showed different responses. Notably, expression of the HsfA2a gene was predominantly upregulated in the flag leaf and spikelets under heat stress in M9962. Therefore, it can be concluded that heat stress has severe effects on the stamen, and that different genotypes have different susceptibilities to heat stress.


2000 ◽  
Vol 125 (2) ◽  
pp. 265-270 ◽  
Author(s):  
A.M.S. Nyomora ◽  
P.H. Brown ◽  
K. Pinney ◽  
V.S. Polito

The effect of boron (B) on in vivo and in vitro development of almond [Prunus dulcis (Mill.) D.A. Webb (syn. P. amygdalus Batsch)] pollen and pollen tubes and the resultant effect on fruit set was studied in mature trees. The cultivars Mono (pistil donor) and Butte (pollinizer) in an orchard with low soil B in Fresno, California were sprayed with B at 0, 0.8, 1.7, or 2.5 kg·ha-1 during Fall 1993. Pollen viability as indicated by the fluorescein diacetate method (FDA) was >85% and was not affected by field-applied B, however, in vivo pollen germination and tube growth were enhanced by foliar-applied B. More effect of applied B on in vivo growth appeared as pollen tubes progressed toward the ovary. For in vitro germination, foliar-applied B reduced bursting of tubes, and addition of B to the culture media significantly increased pollen germination and pollen tube growth.


1969 ◽  
Vol 9 (41) ◽  
pp. 636 ◽  
Author(s):  
D Pasternak ◽  
GL Wilson

Sorghum plants were exposed at head emergence to simulated heat waves for five days, and subsequent grain production observed. Comparisons were made between relatively dry heat (108�F, 41 per cent RH by day and 90�F, 53 per cent RH by night), more humid hot conditions (107�F, 70 per cent RH-90�F, 70 per cent RH), and ambient (81�F, 64 per cent RH-71�F, 85 per cent RH). Whole inflorescences or portions that had emerged before heat application were little affected, whereas most enclosed flowers were killed. High temperature was responsible, humidity having little effect. Grain yield depended on the resulting number of grains. There was some loss of pollen viability in the dry heat treatments, but not sufficient to affect seed set.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Melekber Sulusoglu ◽  
Aysun Cavusoglu

Pollen quality is important for growers and breeders. This study was carried out to determinein vitropollen viability and pollen germination in seven genotypes of cherry laurel (Prunus laurocerasusL.). Two pollen viability tests, TTC (2,3,5-triphenyl tetrazolium chloride) and IKI (iodine potassium iodide), were used. Pollen traits of genotypes were studied using anin vitromedium containing 0%, 5%, 10%, 15%, and 20% sucrose to determine the best sucrose concentrations for germination. In the second step, the germinated pollen was counted 1, 4, 6, 10, 12, 24, and 48 hours later until there was no further germination. The viability rates were different according to genotypes and tests used. The IKI and TTC staining tests and pollen germination had low correlation (r2= 0.0614 andr2= 0.0015, resp.). Painted pollen rate was higher and pollen was well-stained with IKI test and pollen viability estimated with TTC staining test was better than that estimated with the IKI staining test. 15% sucrose gave the best germination rates in most of the genotypes. Pollen germination rates were recorded periodically from one hour to 48 hours in 15% sucrose and the results showed that pollen germination rates increased after 6 hours of being placed in culture media.


2007 ◽  
Vol 21 (1) ◽  
pp. 23-29 ◽  
Author(s):  
Ian C. Burke ◽  
John W. Wilcut ◽  
Nina S. Allen

A high proportion of viable pollen grains must germinate to study the physiology of pollen growth to reduce the confounding effects of environmental influences on pollen germination. The objectives of this study were to evaluate the nuclear state and develop a suitable medium and culture method for in vitro germination of johnsongrass pollen. Johnsongrass pollen was trinucleate, and in vitro tests for pollen viability using Alexander's stain and a fluorochromatic reaction method (FCR) indicated johnsongrass pollen was viable (92.6 to 98.4%). A factorial treatment arrangement of four concentrations of sucrose, two concentrations of boric acid, and two concentrations of calcium nitrate were used to determine the optimum pollen-germination medium composition in suspension culture, agar culture, and cellophane membrane culture. Germination was highest in a suspension culture with a medium containing 0.3 M sucrose, 2.4 mM boric acid, and 3 mM calcium nitrate. Pollen germination using this medium was 78.9% when anthers were harvested just before anthesis.


Silva Fennica ◽  
2019 ◽  
Vol 53 (2) ◽  
Author(s):  
Yan Liu ◽  
Yuan Zhang ◽  
Qing Zhou ◽  
Jian Wu ◽  
Pingdong Zhang

Colchicine is widely used as a mutagen to induce production of diploid gametes in plants. However, whether colchicine affects induced pollen viability remains unclear. To clarify whether colchicine affected the viability of induced pollen, we induced production of diploid pollen by colchicine, followed by pollen germination and crossing induced pollen with normal gametes to produce triploid in Carrière. The results showed that the predominant meiotic stages and the number of colchicine injections had significant effects on the occurrence rates of induced 2n pollen. When the colchicine injection was given at diakinesis, a significant decrease in the pollen production per bud was observed ( < 0.001). The morphology of the colchicine-induced 2n pollen was similar to that of the natural 2n pollen in its ectexine structure. The pollen germination experiments revealed that there was also no significant difference in germination rates between the induced diploid pollen and natural 2n pollen grains, and 68 triploids were created by crossing colchicine-induced pollen. Our findings revealed that colchicine injection could induce to produce 2n pollen and will not lead to dysfunction of induced diploid pollen.in vitroPopulus tomentosapP. tomentosa


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