HLB-tolerant rootstocks can aid productivity and tree survival, especially when integrated with other strategies. Australian limes demonstrate HLB tolerance, and their genetics can enhance HLB-susceptible citrus through conventional breeding.
Researchers at the University of Florida Institute of Food and Agricultural Sciences Citrus Research and Education Center (UF/IFAS CREC) have spent the last decade developing HLB-tolerant hybrids by crossing various Australian lime species. These hybrids have shown improved HLB tolerance in field conditions, with many trees remaining HLB-negative even in endemic settings.
Several hybrid cuttings were rooted and grafted with Valencia budwood to study HLB progression in CLas-infected trees. A recent greenhouse study featured the potential of these hybrids for enhancing HLB tolerance in Valencia sweet orange. Among the tested hybrids, both mandarin × finger lime (MFL1–98) and pummelo × finger lime (PFL2–61) showed similar graft success and scion vigor to the Swingle rootstock. PCR analysis indicated a low infection rate in the Valencia scions grafted onto these hybrids, and the hybrid root tissues remained CLas-free.
Ongoing research will continue evaluating the commercial application of these rootstocks. Upcoming field trials will further investigate the impact on tree growth and fruit quality, utilizing this germplasm.
Source: Citrus Industry
