Morphotype relationships in Lima bean (Phaseolus lunatus L.) deduced from variation of the evolutionary marker phaseolin

Phaseolin diversity in wild Lima bean (Phaseolus lunatus L.) in American centres of origin

“…Some accessions show patterns analogous to the M pattern described in cultivated forms (Figure l, lane 1). Most wild accessions, however, show phaseolin patterns that are not encountered in the cultivated forms (Lioi, 1994). The M1 pattern is intermediate between M and M2 (Figure l, lanes 2, 3).…”

“…The two subunit classes derive from the cleavage of larger precursors with Mw of about 58 000 and 54 000 Da; a residual amount of these latter is still present in the mature cotyledons (Daminati et al, 1994;Sparvoli et al, 1996). In the M pattern type, phaseolin is organized in a similar way, but the polypeptides show notable differences in molecular weights (Lioi, 1994).…”

“…Recently, given the high occurrence of intermediate forms (Maquet et al, 1990;Esquivel et al, 1990) and the results of biochemical evidence (Lioi, 1994), the terminology large-, intermediate-, and small-seeded morphotypes has been adopted. Different authors have tried to locate the origin of P. lunatus in the New World and to explain its domestication.…”

“…The identification of polypeptides that can be related to phaseolin among the Lima bean seed storage proteins (Daminati et al, 1994;Sparvoli et al, 1996) and its use as an evolutionary marker (Lioi, 1994), confirmed the existence of two gene pools, a Mesoamerican and an Andean one_ Cultivated small-and intermediateseeded genotypes (Sieva, Potato, Sieva-Potato, and Sieva-Big Lima), when analyzed on the basis of variation of the seed storage protein phaseolin, showed the M and MA pattern types, confirming that they originated in the same gene pool. On the other hand, cultivated large-seeded morphotypes (Big Lima) showed the A pattern, confirming that they belong to a distinct gene pool (Lioi, 1994).…”

Phenotypic diversity in lima bean landraces cultivated in Brazil, using the Ward-MLM strategy

“…Big Lima represents the A gene pool, while Sieva and Potato represent the MI and MII gene pools. Lima bean has a high level of polymorphism, mainly related to seed traits (Lioi, 1994). This aspect was firstly used to recognize the main gene pools and later to characterize the genetic diversity of this species (Santos et al, 2010).…”