Evaluation of some grain sorghum hybrids under saline conditions and identification biochemucal genetic markers

Abstract: Fourteen grain sorghum hybrids, which were developed from seven exotic cytoplasmic male sterile (A-lines) and two restorer lines (R-lines), were evaluated in a field experiment under control and saline conditions, at Nubaria Agric. Res. Station in two growing seasons 2001 & 2002. The genetic parameters were estimated by using line x tester analysis.

Mean squares due to genotypes, years and salinity were highly significant for almost all studied traits i.e., 50% heading, plant height (cm), leaf area, no of green leaves, panicle length, 1000-kernel weight and grain yield/plant (g). Mean squares due to interaction between genotypes and salinity were significant for 50% heading, leaf area, 1000-kernel weight and grain yield/plant.

Analysis of salinity sensitivity index (SI) showed non-significant differences between the two male parents while differences among females and among hybrids were significant indicating the important role of heterotic effects on sorghum tolerance to salinity. Estimated SI values indicated that hybrids were more tolerant to salt stress than parental lines. The hybrids ICSA-37 x Dorado (H3), ATX-631 x Dorado (H7), ICSA- 1 x ICSR-91022 (H8), ICSA- 37 x ICSR-91022 (H10), and ICSA- 88015 x ICSR-91022 (H13), were the most tolerant hybrids, where SI estimates were 0.36, 0.62, 0.14, 0.68, and 0.42, respectively. On the other hand the parents ICSA- 37 (P3) and ICSR- 91022 (P9) were salt tolerant and had SI values of -0.70 and -0.62 respectively. Estimates of general and specific combining ability effects of SI showed that ICSA- 37 was the best general combiner for salinity tolerance and hybrids ICSA- 1 x ICSR-91022 and ICSA- 37 x Dorado were the best with regard to specific combining ability. Heterosis as percentage of F1 relative to the lower parent showed the same hybrids had the best heterobiltioses under salinity conditions.

SDS-PAGE protein banding patterns for water soluble fraction of seed storage proteins was successful in generating biochemical genetic markers related to salt tolerance in sorghum. Four bands with the molecular weights of 72.64, 59.59, 46.37 and 22.75 KDa were absent under salt stress conditions in most of the hybrids and could be considered as negative markers; while, a single band of 37.19 KDa was found to be expressed only under salt conditions and could be considered as a positive marker. The tolerant hybrids ICSA-37 x Dorado (H3), ATX-631 x Dorado (H7), and ICSA- 37 x ICSR-91022 (H10) in addition to the tolerant parents ICSA- 37 (P3) and ICSR-91022 (P9) exhibited almost the same banding patterns under control and stress conditions indicating that they were less suffering under salt stress and could store almost normal protein in their seeds. The previously mentioned parents are recommended to be included in breeding programs for salt tolerant sorghum hybrids.

Key words: Grain sorghum, Hybrids, Heterobiltioses, Salinity tolerance, Biochemical genetic markers, Protein electrophoresis, SDS-PAGE
Publication year 2003
Pages 183-203
Availability location معهد بحوث المحاصيل الحقلية-مركز البحوث الزراعي -8ش الجامعه -جيزة
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