The History of Domestication and Selection of Lucerne: A New Perspective From the Genetic Diversity for Seed Germination in Response to Temperature and Scarification

Lucerne (Medicago sativa), a major perennial pasture legume, belongs to a species complex that includes several subspecies with wild and cultivated populations. Stand establishment may be compromised by poor germination. Seed scarification, deterioration and temperature have an impact on germination. The objective of this study was to analyse the genetic diversity of lucerne germination in response to three factors: (1) temperature, with seven constant temperatures ranging from 5 to 40°C, was tested on 38 accessions, (2) seed scarification was tested on the same accessions at 5 and 22°C, (3) seed deterioration was tested on two accessions and two seed lots at the seven temperatures. The germination dynamics of seed lots over time was modelled and three parameters were analysed: germinability (germination capacity), maximum germination rate (maximum% of seeds germinating per time unit), and lag time before the first seed germinates. Seed scarification enhanced germinability at both temperatures and its effect was much higher on falcata and wild sativa accessions. Incomplete loss of the hardseededness trait during domestication and selection is hypothesised, indicating that the introduction of wild material in breeding programmes should be followed by the selection for germinability without scarification. Seed lots with altered germinability had low germination at extreme temperatures, both cold and hot, suggesting that mild temperatures are required to promote germination of damaged seed lots. A large genetic diversity was revealed for germination (both capacity and rate) in response to temperature. All accessions had an optimal germination at 15 or 22°C and a poor germination at 40°C. The sativa varieties and landraces had a high germination from 5 to 34°C while the germination of falcata and the wild sativa accessions were weakened at 5 or 34°C, respectively. These differences are interpreted in terms of adaptation to the climate of their geographical origin regions in order to escape frost or heat/drought risks. These new findings give insights on adaptation and domestication of lucerne in its wide geographic area. They suggest further improvement of germination is needed, especially when introducing wild material in breeding pools to remove scarification requirements and to limit differences in response to temperature.

SEED PHYSICAL SCARIFICATION AND GROWING MEDIA ON VIGOR OF Moringa oleifera

This experiment was aimed to reveal the effect of seed physical scarification and various growing mediaon vigor of Moringa oleifera. This study was conducted in greenhouse and consisted of two phases ofexperiment; first was studied the effect of physical scarification on seed germination of M. oleifera and thesecond was studied the effect of seed physical scarification and various sub optimum growing media onvigor of M. oleifera. The germination test was arranged in randomized completely design with 4 treatmentsthat were P0 = non scarification, P1 = one side scarification, P2 = two sides scarification, and P3 = full sidescarification. The variables measured were germination percentage (%) and seedling dry weight (g/plant).The second study was arranged in a factorial randomized completely design with the four treatments ofscarification (P0, P1, P2 and P3) over six growing media (sands, bricks, bricks and sands mixture, bricksand soils mixture, soils and sands mixture, and soils). The variables observed were petioles number, plantheight (cm/plant), and plant dry weight (g/plant). The scarification was significantly affect (P<0.05) thegermination percentage and seedling dry weight. Scarification and growing media also affected the vigorof M. oleifera significantly (P<0.05). Two side seed scarification improve the germination and seedling dryweight instead of control. Combination of scarification in two sides and growing media of soils and sandsmixture given the highest vigor of M. oleifera reflected on petioles number, plant height, and plant dry weight. Keywords: germination, M. oleifera, scarification, sub optimum media, vigor

Skarifikasi Benih Makadamia (Macadamia Integrifolia Maiden & Betche) Menggunakan Suhu Perendaman dan Pengeringan Secara Bergilir

<em>Macadamia can be propagated using seeds. However, the seed is difficult to germinate due to shell hardness. This study aimed to determine the proper combination of seed scarification needed to break the seed coat using rotational soaking and drying at varied temperatures. The experiment was conducted at Manoko Experimental Station and BPTP of West Java from December 2018 to April 2019, used a Randomized Complete Block Design in 15 treatments and 3 replications. The treatments were: (1) water soak (WS) 24^oC+drying 35^oC; (2) WS 35^oC (first day)+WS 24^oC+drying 35^oC; (3) WS 50^oC ( first day)+WS 24^oC+drying 35^oC; (4) WS 35^oC everyday+drying 35^oC; (5) WS 50^oC everyday+drying 35^oC; (6) WS 24^oC+drying 40^oC; (7) WS 35^oC (first day)+WS 24^oC+drying 40^oC; (8) WS 50^oC (first day)+WS 24^oC+drying 40^oC; (9) WS 35^oC everyday+drying 40^oC; (10) WS 50^oC every day+drying 40^oC; (11) WS 24^oC+drying 45^oC; (12) WS 35^oC (first day)+WS 24^oC+drying 45^oC; (13) WS 50^oC (first day)+WS 24^oC+drying 45^oC; (14) WS 35^oC everyday+drying 45^oC; and (15) WS 50^oC everyday+drying 45^oC. Variable observed were moisture content of seeds, rate and percentage of seeds cracking, and length of seeds radicle. The results showed that alternating temperature during soaking and drying affected seed scarification. The fastest seed breaking rate is 3.27 days in soaking at 50^oC everyday for 18 hours, with 45^oC drying temperature for 6 hours, the percentage of seed breaking reached 87.67%.</em>