A meta-analysis of bioenergy conversion relevant traits in sorghum landraces, lines and hybrids in the Mediterranean region

Sorghum crop demonstrated high yield potential under drought and wet environments with a betterenergy balance than several cultivated plants. Sorghum biomass can contribute to solving the pressingissue of reducing reliance on fossil fuel. Africa and Asia are sorghum centers of diversity, and landracestherefrom can be of great breeding and production interests in the Mediterranean region. Several worksevaluated biomass sorghums, but results on comparative performance between lines, landraces andhybrids are lacking. The objective of this work was to assess the performance of these genotypic groupsfor traits relevant for biofuel conversions, by carrying out a meta-analysis of data from twenty-fourtrials conducted in different Mediterranean locations in Italy over seven years. Obtained results showedsorghum hybrids as the best biofuel feedstock option as they outperformed landraces and lines for mosttraits including biomass yield. Landraces represented an attractive alternative to hybrids and lines as theyoutyielded lines and were second only to hybrids in terms of biomass production and cellulosic content.Biomass yield advantage was explained by increased plant tallness and cellulosic content in hybrids,and cellulosic content in landraces, and to a lesser extent, by plant maturity in hybrids and landraces.Based on biomass quality and quantity, hybrids and landraces can supply thermal, thermochemical andbiochemical biofuel conversion industries. Sorghum lines could be better used in first generation biofueland energy bioconversion technologies requiring lower lignin containing feedstocks. Landraces and linescould be targeted to areas where hybrid seed production industry is not developed