Phenotype and seed production among hyacinth bean (Lablab purpureus L. Sweet) accessions rescued using hydroponic techniques

Authors: Morris, John - Brad

Submitted to: Seed Technology Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/14/2013
Publication Date: 11/17/2014
Citation: Morris, J.B. 2014. Phenotype and seed production among hyacinth bean (Lablab purpureus L. Sweet) accessions rescued using hydroponic techniques. Seed Technology Journal. 35(2):189-198.

Interpretive Summary: Hyacinth bean is a vegetable, forage producing plant as well as an ornamental plant used in home gardens. Many samples of hyacinth bean will not flower during their juvenile phase in Byron, GA, while others will only produce few seeds when grown in the field. A study was conducted to identify whether or not hydroponic systems could be used to increase hyacinth bean seed numbers. Twenty-five hyacinth bean samples were grown in the Byron, GA field. Vegetative stem cuttings from each hyacinth bean plant were placed in a hydroponic cloning system during the Fall of 2011. Most of the cuttings produced healthy root systems after 1-2 weeks. Healthy stem cuttings were then transplanted to plastic pots containing potting soil and grown in the greenhouse. In addition, 30-day old hyacinth bean seedlings originating from a low seed producing sample were placed in a nutrient film technique (NFT) hydroponic system during the first week of May, 2011. High quality seeds and seed numbers ranging from 20-1,127 seeds per sample were produced using the cloning hydroponic system while 1,629 seeds were produced using the NFT system. Hydroponics are useful techniques to rescue juvenile and freeze sensitive hyacinth bean samples for quality seed numbers.

Technical Abstract: Hyacinth bean, Lablab purpureus L. (Sweet) is a legume used as a vegetable, forage, and in home gardens as an ornamental plant. Many accessions do not flower during their juvenile period in Byron, GA. Other hyacinth bean accessions produce few seed when regenerated in the field. This study was conducted to develop a hydroponic cloning and a nutrient film technique (NFT) for seed regeneration from juvenile, freeze-sensitive accessions and a low seed producing hyacinth bean accession. Twenty-five juvenile and freeze sensitive hyacinth bean accessions were planted at Byron, GA during 2011. Four mature stem cuttings per accession with 3 true leaves each were removed from plants and placed in a hydroponic cloning system inside a greenhouse during the Fall of 2011. Most of the stem cuttings developed healthy root systems after 1-2 weeks. Two to 4 well developed stem cuttings per accession were transplanted to potting soil in plastic pots and placed in a greenhouse. Fourteen 30-day old seedlings (from a low seed producing hyacinth bean accession) growing in jiffy pots containing potting soil were placed in an NFT system inside a high tunnel during the first week of May, 2011. High quality seeds ranging from 20 to 1,127 seeds per accession were regenerated from clones while 1,629 seeds were successfully regenerated from plants growing in the NFT system. The coefficient of variation for seed number was 59 indicating a fairly low amount of variation. Accessions in cluster group IV showed closer genetic relationships than those in all other groups. The first principal component was most correlated with branching and seed yield. These are excellent techniques to rescue juvenile and freeze sensitive hyacinth bean accessions for quality seed regeneration and can be evaluated for phenotypic variation.