Latest Research on Sorghum genotypes: Feb 2021

Comparison of two Sorghum genotypes for sugar and fiber production

A comparative analysis of the growth and yield performances of two late maturing and productive sweet and fiber sorghums has been conducted, with the perspective of their introduction in temperate Italian climate areas as competitive multi-product crops. Sweet type sorghum `Wray’ (Sorghum bicolor (L.) Moench ssp. bicolor), and the nonsweet type, `H173′ (hybrid Sorghum bicolor (L.) Moench×Sorghum docna var. technicum), were grown in a field trial under well-watered conditions in northern Italy (latitude 44°3′N, longitude 11°2′E). During the crop cycle, growth analysis were performed by collecting data from both non-destructive and destructive samplings. Fundamental growth indexes were calculated as a function of accumulated growing degree days (GDD) from sowing. Yield traits were evaluated at soft dough maturity. Sweet and fiber crops reached soft dough maturity after 1250 GDD and did not statistically differ for total and main stem yields. Mean values of 27 and 20 t ha−1 dw, respectively, were detected. The sucrose content was more than three times higher and the cellulose and lignin contents 40–50% lower in `Wray’ as compared to `H173′, whereas the level of reducing sugars was similar. Both sorghum types can be considered as interesting new crops which might provide an energy production higher than 10 000 kcal m−2, a potential production of around 6000 l ha−1 of ethanol (sweet), and up to 15 t ha−1 of structural polysaccharides (fiber). The rate of leaf formation on the main stem and their final number were similar between the two genotypes. Until the growing differentiation point, one new leaf was visible every 40.5 GDD, thereafter the same growth process required around 123 GDD. During the period of early leaf formation, the fiber type showed a greater tillering ability which positively affected early canopy area and growth parameters. On the other end, the sweet sorghum crop presented enhanced dry matter accumulation capacity after the growing differentiation point as compared to the fiber crop (42.7 and 27.7 g m−2 d−1, respectively). This could be the result of higher leaf thickness and leaf area duration. [1]

Flavonoid composition of red sorghum genotypes

The effect of genotype on flavonoid composition was investigated in 13 sorghum varieties using HPLC-DAD. Sorghums with red/purple secondary plant colour had the highest levels of 3-deoxyanthocyanins (32–680 μg/g) with the black pericarp sorghums having the highest. Sorghums with red secondary plant colour had a high proportion of apigeninidin compounds (66–89%), which suggested that secondary plant colour affects 3-deoxyanthocyanin composition. Red pericarp sorghums with tan secondary plant colour had the highest levels of flavones (60–386 μg/g). Flavanones were also detected in all sorghums with a red pericarp (8–48 μg/g) and secondary plant colour did not affect their levels (p > 0.05). The elevated 3-deoxyanthocyanin levels in the black sorghums were due to their pericarp colour. Black sorghum panicles that were exposed to sunlight during their development had three times more 3-deoxyanthocyanins (617 μg/g) than those that were covered with a paper bag (212 μg/g). This study showed that flavonoid levels and composition were affected by sorghum genotype. This information will help sorghum breeders to produce sorghum genotypes with maximum levels of desired flavonoids. [2]

Selecting sorghum genotypes expressing a quantitative biosynthetic trait that confers resistance to Striga

One of the best characterized mechanisms of host resistance to witchweeds (Striga spp.) is exudation by host plant roots of relatively low amounts of compounds that Striga seeds require as stimulants for germination. We find that all sorghums tested, regardless of whether they are susceptible or resistant to Striga, produce equivalent amounts of sorgoleone, the alkylated hydroquinone we previously identified from sorghum root exudate as the first host-derived Striga germination stimulant to be characterized. In contrast, some highly resistant sorghums produce relatively tiny amounts of another germination stimulant, as yet unidentified but with properties quite different from sorgoleone, whereas all susceptible sorghums produce relatively large amounts. A simple, rapid and nondestructive agar gel assay which detects this second stimulant, but not sorgoleone, reliably distinguishes low (Striga resistant) and high (Striga susceptible) stimulating parental genotypes and progenies from crosses among them. Because the lack of a reliable and rapid method for screening germplasm and breeding progenies has hampered the development of crop varieties resistant to Striga, this gel assay is expected to greatly enhance the efficiency of sorghum breeding for Striga resistance. [3]

Phenotypic Diversity of Selected Dual Purpose Forage and Grain Sorghum Genotypes

Aims: To study the phenotypic diversity of 25 forage and 45 grain sorghum genotypes for dual purpose as food and feed and to identify traits that might contribute to genetic improvement.

Study Design: A 7 × 10 alpha lattice design was used with two replications at two sites.

Place and Duration of Study: The study was conducted at Makerere University Agricultural Research Institute Kabanyolo (MUARIK) and National Semi Arid Resources Research Institute (NaSARRI) in Uganda between September to December, 2013 (Season 1) and April to July 2014 (season 2).

Methodology: Morphological and agronomic data were taken for each genotype from each environment in the two seasons and subjected to combined analysis of variance separately for the grain and forage sorghums. Multivariate analysis was done based on principle component and cluster analyses in which grain and forage sorghum genotypes were combined.

Results: Analysis of variance revealed significant differences (P < 0.001) among the genotypes for biomass, grain yield, plant height and days to flowering indicating the possibilities of improving these characters through phenotypic selection. Cluster analysis grouped the genotypes into 3 clusters with cluster 1 retaining majority of the forage genotypes characterised with high biomass, Cluster 2 containing a mixture of the forage and grain sorghums characterised with high grain yield while cluster 3 contained only the grain sorghums. The first four principle components explained 89% of the total variations observed in the genotypes.

Conclusion: Based on the performance of genotypes in this study, simultaneous selection of genotypes exhibiting moderate to high levels of grain and fodder traits resulted in twelve genotypes being selected as parents for the development of dual purpose sorghum cultivars. [4]

Yield Adaptability and Stability of Grain Sorghum Genotypes across Different Environments in Egypt using AMMI and GGE-biplot Models

Presence of G×E interaction reduces the correlation between genotypic and phenotypic parameters and complicates progress of selection. Among several methods proposed for evaluation of the GE interaction, the AMMI and GGE-biplot are the most informative models. The objective of this study was to estimate the G×E interaction in sorghum parental lines and to identify sorghum B-lines of stability and adaptability across different environments using the AMMI and GGE-biplot models. Six environments with 25 sorghum B-lines were conducted at two locations in Egypt (Giza and Shandaweel) in two years and two planting dates in one location (Giza). A randomized complete block design was used in each environment (yield trial) with three replications. The AMMI analysis of variance indicated that the genotype (G), environment (E) and GE interaction had significant influence (p≤0.01) on sorghum grain yield. Based on AMMI model, BTX TSC-20 followed by ICSB-1808 showed both high yielding and stability across the test environments. However, ICSB-8001 (G11) and BTX-407 (G21), showed maximum stability, but with moderate grain yield. Based on GGE-biplot method, BTX TSC-20 (G25) was the winning genotype for the mega-environment which consists of E1 and E3, ICSB-14 (G3) for the mega-environment (E2 and E4), while BTX 2-1 (G20) for E5 mega-environment, ICSB-88003 (G12) and ICSB-70 (G6) for the mega-environment E6. These genotypes are the most adapted to the respective environments. [5]

Reference

[1] Dolciotti, I., Mambelli, S., Grandi, S. and Venturi, G., 1998. Comparison of two sorghum genotypes for sugar and fiber production. Industrial Crops and Products, 7(2-3), pp.265-272.

[2] Dykes, L., Seitz, L.M., Rooney, W.L. and Rooney, L.W., 2009. Flavonoid composition of red sorghum genotypes. Food Chemistry, 116(1), pp.313-317.

[3] Hess, D.E., Ejeta, G. and Butler, L.G., 1992. Selecting sorghum genotypes expressing a quantitative biosynthetic trait that confers resistance to Striga. Phytochemistry, 31(2), pp.493-497.

[4] Chikuta, S., Odong, T., Kabi, F. and Rubaihayo, P. (2015) “Phenotypic Diversity of Selected Dual Purpose Forage and Grain Sorghum Genotypes”, Journal of Experimental Agriculture International, 9(6), pp. 1-9. doi: 10.9734/AJEA/2015/20577.

[5] Al-Naggar, A. M. M., El-Salam, R. M. A., Asran, M. R. and Yaseen, W. Y. S. (2018) “Yield Adaptability and Stability of Grain Sorghum Genotypes across Different Environments in Egypt using AMMI and GGE-biplot Models”, Annual Research & Review in Biology, 23(3), pp. 1-16. doi: 10.9734/ARRB/2018/39491.

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